hurtful boobies!

Hey ladies! So I love when my bf gives my boobs attention during sex, as I'm sure most of you do too! I'm all for the nibbling, sucking, and grabbing usually..but recently it's been opposite. Last night it was really painful and then today my boobs feel extra heavy and just sore in general. My period isn't for another 2 weeks and I'm just wondering for some insight. It could be that my body is changing and the weight could be the issue? Just looking for some insight, my boobs are already big enough (DDD).