Hello and welcome!
I've thought about using a menstrual cup as well. Actually, when the Instead cup first came out I tried it.
There are quite a few cups available now. The sizes of the actual cups vary from brand to brand. a large of one brand may actually be bigger or smaller than a large of another brand. Im actually looking at a lady cup also. I think i need something a bit shorter since my cervix can be quite low at times. I havent trimed the stem off yet incase someone wanted a picture i think i wont be able to feel it after i cut the stem off. I