sore breast

so I ended my period like 4-5 days ago and I am really confused on why my boobs are still sore? I don't think I could be pregnant bc I only had sex once before my last period and if I was preg I don't think my period would've came. It was a normal period so I'm not worried about being pregnant. Anyways im 17 so could this be that my boobs are started to grow again? Or what idk usually my boobs stop being sore right when my period starts but not this time girl 😂😂