another boring what size question

hi! so I've been using cups for a year or so, and recently switched birth controls. now, I've been spotting a lot, and my cervix has been really really low. I've been using my MCUK small, but even that seems too long right now. I was thinking of getting a Meluna mini small, but it says that overweight people should get the medium. I think I'd like the length of the small, but would it be too narrow? any other curvacious ladies with low cervixes have an input? thanks!