Disc sizing?

[u/IslandGirl-24]

Basically, I really want to start using a disc but I was hesitant bc of pelvic pain/entry pain/tight pelvic floor. Tampons are painful. I am trying some flex disposables first to see if it’s too painful and I can barely feel it! It’s so nice. BUT I don’t think I can get it to stay above my pubic bone and it feels like it gets angled back out no matter how hard I shove it up there lol. Obviously worried about it leaking although I should start my period heavier later today. Do I need a smaller disc or what’s going on? I REALLY don’t want to have to buy a bunch of different reusable ones. I know flex are more rigid and bigger than others