Yeah I think it’s normal because the exact same happened to me, I’m now 10 days post op but felt the worst the day after the op and a few days after that.. It’s probably because the anaesthetic is wearing off because it can take 24-48 hours depending on how you react to it.. Also you are probably quite swollen which is why your sports bra feels so tight… I have a Macom bra in a medium, have to keep 4 of the hooks undone and it still felt too tight lol… It gets easier after a few days though, just make sure you get plenty of rest and don’t overdo it xx