Eh sayang, breast tenderness and swelling is super normal in early pregnancy, hormones memang kerja macam gila at 5 weeks! A few of us went through the same thing and one mum friend said hers was lopsided jugak for a bit, so don't worry lah, it settles down. That said, since you're noticing quite a bit of asymmetry and heaviness, best check in with your gynae just to be sure everything's on track, better safe than sorry kan, especially this early on.