Sore boobs and back pain?

So I’ve been having trouble w my back hurting and my boobs have been sore, feels like my bra is too tight but I switch out with different bras and it’s the same, even bought a bigger band and cup, nothing. My nipples and boobs are sore and now I’m starting to get worried. My back is in constant pain. There’s no way I can be prego, my boyfriend hasn’t came in me he always finishes off wankin. (Sorry this is awkward as hell to talk about). Idk if my boobs are growing? Ovulation? I have no idea. Anyone ever have this happen to you? Constant back pain, sore boobs for two weeks now, and just today my nipples are sore, I don’t know wth is wrong w me. I go to the gym and workout idk if that has anything to do w it and I’m losing weight so idk why my boobs would be growing (I’m also 21 about to be 22 so I don’t think they’re still growing) I don’t work out my arms, I mainly run and do machines that are for my legs. Idk plz someone help 🤣 I’m confused asf