I am 23 years old, never had a kid... however, i use the large size. the reason i chose the large is because femmecup only comes in one size which is the equivalent of a large, lady cup recommends the age cut off as being 25 (which i'm getting close to), and lunette used to only provide one size as well... recommended for all ages. I figured that a large is only a few millimeters different and I could use it forever anyhow.
ANYWAY... i think the mooncup isn't working due to it's stiffness and "step" style ridges. Do you like a smoother, more flexible cup like the LadyCup would be more suited towards me? Will it be bendy enough to morph into the correct shape no matter how i'm positioned?