Day 1 and 2 I had TERRIBLE leaking. I was having to wear a maxipad, which of course defeats the whole purpose. Every time I sat down, if I concentrated hard, I could feel the cup denting in on the bottom side, losing its seal, and leaking everywhere. When I would remove it, there was hardly anything in the cup. I was trying to sit funny, or stand at my desk, and I still had problems. It was awful. I was very disappointed.
On the night of Day 2, I went running. I wear my cup high, above the pubic bone, and when I got home it was so low I could feel nearly the entire back side of the cup sticking out along the vaginal opening, and the rim was just millimeters from slipping out. Thank goodness it didn't, because it was FULL.
Each time I inserted, I was feeling a dent on the underside of the cup, and actually using my finger to push the vaginal wall out toward the rectum until I felt the cup unfold fully. So that wasn't the problem. I was also doing my best to run my finger around the rim, although it was difficult to reach that far.
After the running incident, I reinserted and went to bed. By some miracle, I woke up in the morning with no leaking, and I felt like the cup had found its correct place. I remembered reading on here a tip about trying to get the cervix inside the rim, which is difficult if the cervix isn't exactly centered at the top of the vagina. If you think of the cervix as a soft, squishy light bulb hanging down at the top of the vagina, with the opening being the little GE symbol on the bulb, you can imagine what I am talking about. I think my cervix is off to the side a bit, and I was smooshing it but not having the opening actually inside the rim. I emptied the cup in the morning and reinserted, working really hard to feel my way around the rim and try to push anything that felt like my cervix toward the center of the cup. When I was done, I noticed that the tail of the cup was at a diagonal, not in line with the labia, but pointing somewhat off to the side! So I was right! When my cup is inserted correctly, it is not symmetrical or centered. And getting it over the cervix allows it to move up higher, and not be squished when I sit down. When I was done inserting, I actually felt the worry about leaking go right out of my mind. I just KNEW it would be fine. I rode my bike to work and when I got there, no leaking! Sat down - no leaking!
I wanted to share this with all who are having problems, because although I saw the links about "tilted cervix" I never thought to click on them as a solution to my problem. I am very happy that I can now use my cup the way it was intended.