Boobs🍒

Does anyone else's boobs change shape?? Like sometimes mine will be really round and perky and then other times they'll be saggy and look awful. Really knocks my confidence because I don't know what they'll look like when I take my bra off infront of my boyfriend. I'm only a 34B so it's not like they're getting weighed down, and I'm only 18 so they shouldn't be sagging yet.