Recently I've been thinking about switching over to menstrual cups. However there is one thing I'm kind of confused about. I'm under 30 and don't have any children, in that aspect most companies suggest a size 1. However I have a moderate to heavy flow, need to change super tampons every hour and a half to two hours on my heaviest days, so I was wondering whether I'd have to stick to size one or would a size two be a better option considering capacity? I'm 5'7, 150lbs, average build, with a average cervix, nothing too high and not low either.
Basically I'm just confused about the sizing? Should I strictly look at size 1 or consider different options?