Switching to the diva cup: was super uncomfortable for me

So I’ve been wanting to try out the cup for a while now, and finally got one today. My flow is pretty heavy right now because I just got my period today. I put the cup in and used both folding methods, the first try was so uncomfortable, and it missed a little bit of blood (thankfully I was wearing a liner). Second time, tried the other folding method and was okay..ish until maybe 15 minutes later where it felt pretty moist down there, missed more blood🙄 finally I just decided to take it out and maybe try again tomorrow. Why is it uncomfortable for me? I had no problem inserting it and taking it out, I felt the suction as I took it out so I’m assuming I put it in the right way. I also know I got the right size (the smaller one), as there are two sizes