Leaking problems

Hello everyone,

I've been researching menstrual cups and watching the community for a while now, and last month I got to try out my first cup but had a bit of a problem.

I bought a Lena cup small, since I have a medium cervix. I experienced leaking from the second day of my period and I couldn't solve it until the end. I checked the rim, it was fine, but a felt something outside of the cup which could have been my cervix. I'm not sure about it because while using the cup it seemed like half of the blood ends up in the cup and the other half leaks. I might also have a problem with the seal becasue I can't go to the toilet with my cup in, it would slip down. 

I read that I should rotate the cup, I tried that a few times and didn't help, but will try again during my next period. Could you give some tips on how to do that, because I can't get a hold of the cup when it's fully inserted.

Is it possible that my cervix is outside of the cup but blood still gets in there? 

Thank you for your help in advance! I really hope it'll work!