So I made a couple of posts earlier on talking about how I went from Insteads to a size 1 Diva Cup to a size 2 Mooncup (US) (even though I'm 21, and have never given birth).
After just completing my cycle, I think I've found it, I think I've found "the one".
SOLUTION: In the first couple of hours I had the cup in, it leaked. I just don't get the whole, "push it in until it's comfortable". Having tried everything with my divacup, I thought back to my Insteads. With Insteads you place the rim of the cup behind your pubic bone, so I figured, maybe the same would work with my mooncup. I turn the cup 360 both ways, make sure it pops open and I push it in until the base of the cup is under the pubic bone. Then I kegel it to make sure it pushes right under it. I haven't leaked since.
I just completed my cycle with amazing, life-changing results. I kind of figured it would leak no matter which cup I used because of my ridiclously heavy flow. But even with a heavy cycle, there was NO leakage! Even while sleeping! How happy was I?!
So that's it. I've read tons of ways to stop leaking, and I haven't seen anything like this, unless I missed it. In which case, the only new info I can add is I LOVE MY MOONCUP <3.