This is my second cycle using the Diva Cup. I'm 36 and I've never given birth but I am a "big girl" (5' 9"). I use the size 2 Diva Cup. When I insert it, it seems to go in with no problem, but within a few minutes, it kind of slides down, so that I can feel the base of it poking out of my vagina when I'm walking. And when I'm sitting, I have a "full" feeling. Kind of like the feeling you get when you use tampons for the very first time. Either A) I'm using it wrong or B) I should be using the smaller size? Can anyone provide some feedback?