I'm a bit unsure about the sizes though. I use the smaller diva cup, but the little chart they use goes both ways for me. I'm an adult woman and my cervix seems to chill quite high up, but I've never given birth, I don't do yoga and I have a sensitive bladder.
I'm leaning towards the smaller cup. That said, the big question is, does having the right size make a difference to how easily it'll pop open? If so, would I be safer going with the smaller or larger?