THIS REPLY HAS FEMALE BIOLOGY IN IT. I shouldn't need to warn people about it, but we are incredibly backward and behind as a people and sometimes talk of menstrual blood and sex bothers people.
I've used a menstrual cup (Lunette) for about 7 years now. (Really, the same one, except the cat ate my first one within the first month. Brat snagged the bag out of my purse and chewed it up in the night!) The vagina isn't very wide and is lined with muscles, so it holds the cup in place over the cervix. Even if it's not right up against it (which it probably won't be, that could be uncomfortable) the cup is held in position. The rim of the cup and the wall of muscle create a barrier so it really doesn't leak (grain of salt*). I sleep with it, run with it, swim in the ocean with it, and have no issues. I used to wear liners just in case, and it will leak if you let it get too full or I dunno, maybe do something rigourous like horseback riding (haven't tried). They only thing you shouldn't do is be inverted (go upside down). I've not heard of it happening, but there's a chance of menstrual blood backflowing into the uterus and somehow causing problems. Really I can't see how, it would have to be a perfect storm to really cause any issues, but I don't really go upside down all that often anyway.)
How often you empty it depends on how heavy your flow is. I was a "super tampon" girl, changing every two hours. Incredibly inconvenient while in high school. But tampons don't absorb very well, and DON'T absorb uterine lining. The cup catches all that and holds about 1.5 ounces. On my Heavy days, (super tampon girl, btw), I empty it in the morning when I wake up, then again at lunch, then when I shower before bed. That's it. (They say not to leave tampons in 8 hours either, but there's really no problem putting one in before bed and leaving it until morning, but I always woke up and change it anyway).
This diagram will show you how to put it in (fold, insert, when it pops open use the end to wiggle it up to where it's comfortable. I then "stir the cup" but inserting a finger and circling the cup to make sure it's really popped open and in right. If it's uncomfortable, simply take it out and try again. Taking it out depends on your model. Mine has a tail and ridges, so I grab the tail and relax my mucles, slowly drawing it out until I can reach root of the tail, then you'll want to pinch the bottom of the cup to pull it out, so you have a good grip and don't spill awkwardly (the tail is soft, not stiff). Just dump in the toilet. If you're right by a sink, feel free to rinse it while sitting, if not, swipe it out with a tissue, and then reinsert it. Yes, your fingers will get dirty, but they do with OB tampons too, and you just wipe off with tissues before dressing and then wash your hands. It's a good idea to give it a water rinse once a day, so I usually do my last pour in the shower. Then I can make sure I get the little holes around the rim clean.
Between cycles it's best to boil the cup in hot water to sterilize it. It will discolor, but that doesn't mean it's not clean. Think, red spaghetti sauce in tupperware in the microwave: always stains the tupperware, but after you wash it, it's clean. You should boil it for about 7 minutes or so. Boring, because you have to hold it with a spoon or it will melt to the pot. Honestly, I'm one lazy chick and have gone 2-3 months between boils.
I love my cup, for a lot of reasons. It cost $50, and I save SO MUCH MONEY on menstrual products. I bought 4 reusable cloth pantiliners to wear over night or on unusually heavy days, but I don't always wear one (my period panties are black anyway, HA). Also, a lot of the discomfort I got during my period disappeared. I still have cramps, but I no longer have vaginal dryness or a cervical pain I couldn't explain. Tip: In a lot of women, the cervix distends slightly during menstruation. Mine couldn't do this properly when I was wearing tampons, and it caused pain. After a couple months of wearing the cup I was "stirring" and felt my distended cervix. I FREAKED OUT, made a gynecologist appointment, who told me everything was normal and it was supposed to do that. Tampons are the GD devil, I tell you. Sex during menstruation is even better; not just because I don't have the vaginal dryness, but because tampons don't absorb well so it was always messy. I still put a towel down just in case, but outside of the usual fluids, I've rarely had menstrual mess. (There's an extra bonus in not wasting cotton material that goes into landfills. Bleaching cotton is way bad for the environment, you know. OH and you're never caught without a tampon, because the thing goes in a little bag in between cycles and goes in your purse or backpack, and is reusable!)
There are technically two sizes, a smaller one marketed for "virgins and young girls" and a slightly larger one. I've never had kids, and (maybe TMI) have been pronounced 'tight'. Tampons were always uncomfortable. BUT I wear the "larger" one just fine.
I'm more than happy to answer any and all questions on menstrual cups. I had a gyno that asked me how I liked mine. After we talked, she said she was going to recommend her daughter try it. 
#TeachersGottaTeach
Edit: Fixed a couple tyops. 
Edited by FelisNoctua, 21 September 2016 - 04:42 PM.
