Why Your Menstrual Cup Doesn’t Fit (and How to Fix It)

Having problems with your menstrual cup? Wondering if you bought the right size? Don’t give up just yet! A correctly-fitting menstrual cup should sit fully inside the vagina with its rim positioned below the cervix, forming a seal without being felt.

If you’ve got a menstrual cup that doesn’t fit, start by making sure you have inserted your menstrual cup correctly and that it's sitting in the right place. The next step is to measure your cervix height and use a cup sizing guide to find the perfect fit. The Ruby Cup sizing guide can be used as a general guide for most cups in the menstrual cup marketplace. Isn’t it so great that there are so many options?

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Before you throw your menstrual cup out the window, let’s take a breath and troubleshoot together to find your perfectly-fitting menstrual cup, just for you! In this post, we will:

1. Review the signs that your menstrual cup doesn’t fit.
2. Identify what it means if you can still feel your menstrual cup and how to fix it.
3. Help you do away with cramps caused by your menstrual cup.
4. Put a stop to surprise leaks.
5. Teach you how to insert your cup to the correct location, not one that is hard to reach, with our step-by-step insertion guide and positioning checklist.

Because there are so many options of cup sizes, finding the right-fitting cup can be a bit of a trial and error process. Your body is amazingly unique and dynamic – your flow, the height of your cervix, and the strength of your pelvic floor muscles all change over time.

How do I know if you’ve got a menstrual cup that doesn’t fit?

Here are some of the key signs that you’ve got a menstrual cup that doesn’t fit:

• You can feel the menstrual cup
• Your menstrual cup causes cramps
• Your menstrual cup leaks
• You have a hard time reaching your menstrual cup or removing it

1. Your menstrual cup may be too big or too small if you can feel it.

Can you feel your menstrual cup coming out of your vagina? Does your menstrual cup seem to be too long? If the cup's stem is poking out, the answer is definitely yes.

A menstrual cup is correctly placed when it sits fully inside the vagina. You don’t feel it. That’s why some cup-lovers say things like “It’s so comfy, I don’t feel it at all, and I sometimes forget I’m even wearing it!”, which probably sounds unimaginable if you’re struggling with your cup.

How to solve this:

There are a couple of reasons having to do with your body that could impact your menstrual cup fit:

• You could have a low cervix.
• You could have a tilted uterus.
• You could have pelvic organ prolapse or decreased pelvic floor muscle strength.

A low cervix means you have a shorter vaginal canal. A retroverted uterus is the name for a tilted uterus, which means that your uterus tips back towards your tailbone. Pelvic organ prolapse happens when your womb, bladder, or bowel bulge into your vagina, according to the NHS. This can also shorten the vaginal canal. People who have a low cervix, a tilted uterus, pelvic organ prolapse, or weakened pelvic floor muscles may find a shorter menstrual cup, such as the Ruby Cup Small, a better fit. 

Because shorter menstrual cups often have less capacity, you can also get a Ruby Cup Medium if you have a heavy period and simply trim the stem. Here’s how to safely cut your menstrual cup stem:

1. Remove your menstrual cup if you are wearing it.
2. Carefully cut the stem with clean scissors.
3. Wear your menstrual cup a few times before trimming.
4. Trim small amounts gradually so you don’t cut too much off by accident.

2. Your menstrual cup causes cramps

While many satisfied Ruby Cup users tell us they have fewer menstrual cramps with their cups, menstrual cups can sometimes cause cramping if they don’t fit. 

• Inserting the menstrual cup too high can lead to the cup suction irritating the nerves on your cervix, causing cramps and discomfort.
• If your menstrual cup is too large or too firm, it may put pressure on the front wall of your vagina, causing pressure on your bladder and urethra, or a cramping sensation.

How to solve this:

Insert your menstrual cup lower in your vagina. Keep a finger in your vagina, by your cervix, to make sure your cup is sitting below your cervix. You may need to trim your stem or try a smaller cup to be able to wear the cup lower in your vagina.

1. Try a softer cup or a smaller cup if you are bothered by bladder-related cramps or pressure.
2. Check that your cup actually is open and forms a good seal with your vaginal walls, not your cervix. After your cup is inserted, run your index finger around the rim to check for creases or folds, which mean your cup hasn’t opened all the way. You can also turn your cup slightly to help it pop open. If you pull gently on the stem and feel some resistance, then you have a good seal! If not, consider trying different folding techniques such as the C-fold, the 7-Fold, or the Punch-Down-Fold.

If trimming or trying different insertion techniques don’t get rid of your cramps, you may want a shorter cup. We recommend a Ruby Cup Small. Not to worry, though. If you purchased a Ruby Cup Medium within the past 120-days, you can use our no-questions-asked, money-back guarantee to switch cup sizes for free.

3. Your menstrual cup is leaking

Leaking is one of the most common frustrations for menstrual cup users, and it's usually caused by either incorrect placement or the wrong cup size. Here's how to troubleshoot:

How to solve this:

• Check your placement. Make sure your cup is opening up below your cervix, not beside it or above it. If you have a low cervix and push the cup too high, it may open alongside the cervix rather than under it, meaning it can't catch your flow properly.
• Make sure the cup is fully open. After inserting, run your index finger around the rim to check for creases or folds. You can also turn the cup slightly to help it pop open. A gentle tug on the stem should meet some resistance — that means you have a good seal.
• Try a smaller size. If the cup is too large, it may not seal properly against your vaginal walls, causing it to become dislodged or fail to open fully.
• Consider your life stage. After pregnancy and childbirth, the vaginal canal can lengthen and pelvic floor tone can weaken, which may affect how well a smaller cup stays in place.

4. Your menstrual cup is difficult to reach

If you’ve chosen a small menstrual cup and have a high cervix, it may sit higher in the vaginal canal and feel harder to reach. This is completely normal and doesn’t mean anything is wrong. Menstrual cups cannot get lost inside your body.

How to solve this:

• Try bearing down or changing your position while trying to reach your cup. Squatting down or putting one foot up on the toilet or the edge of the tub. This will tilt your pelvis, making it easier to reach the high-riding cup.
• Press the cup down with your pelvic floor or stomach muscles until you can reach it (as you do when trying to have a bowel movement).
• Insert your middle finger and thumb until you reach the stem.
• Wiggle the cup down a little bit.
• Once you reach the base, pinch it to break the seal and the suction, then pull it out. Voilà! 

If all this sounds too complicated, you can also try a slightly larger cup, such as the Ruby Cup Medium. It’s a good fit for people with a high cervix.

Ruby Cup is here to help you find the right menstrual cup fit

If you’ve tried all the tips and tricks from our menstrual cup beginners' guide and the ones mentioned above, and you’re still struggling with your period cup, it’s time for a different menstrual cup size.

The Ruby Cup is known as a beginner-friendly and safe menstrual cup. Made from premium medical-grade silicone, it is soft enough to pop open easily yet rigid enough to keep its shape and prevent leaks when in place. Ruby Cup is available in two sizes, giving lots of options for different bodies and flows.

Using our guide to measuring your cervix will help you choose the right size menstrual cup. If it is not quite right for you, you can use our 120-day, no-questions-asked money-back guarantee to return your menstrual cup. We at Ruby Cup know the statistics: Up to 45% of people find menstrual cups difficult to use the first few times. There is a get-to-know-you awkward period when you first start using a menstrual cup, and this includes finding a menstrual cup with the best fit.

Ruby Cup makes it easy and affordable for you to try out two different cup sizes: our Duo Pack offers both the Small and Medium sizes. Some people like having multiple size options to accommodate changing flow over the course of their period, too.

Part of the learning curve for menstrual cups is learning how to correctly insert your menstrual cup to the right place.

A step-by-step guide to inserting your Ruby Cup

1. Wash your hands (and your cup if it is new or you didn’t sterilize it after your last period).
2. Find a comfortable position (squat, one foot up, or sitting on the toilet).
3. Fold the cup to make it smaller and easier to insert.
4. Insert the cup, aiming back towards your tailbone, not straight up like a tampon.
5. Check position and suction, turning slightly or pulling gently to make sure the cup is fully open and sitting below your cervix.

How do you know your menstrual cup is in the right place?

Use this helpful checklist to make sure your Ruby cup is positioned correctly:

• No part of the menstrual cup (including the stem) extends outside of the vagina
• I can’t feel my menstrual cup when I am wearing it
• I don’t have any leaks
• I don’t have any cramps, bladder pressure, or other discomfort
• My cup is sitting below my cervix when I check by keeping a finger in my vagina while inserting my cup