wondering???!

So, my last period started may 28th. As soon as it ended (maybe 4 days) my husband and I had unprotected sex but he did not finish in me. 
I know you can't have symptoms like instantly after but ever since then my boobs have been hurting the entire month of June, BOTH of my nipples and just entire boob in general. It feels extremely sensitive but also a stinging in the nipple area and very heavy.
Since I don't think I'm pregnant, what would be the cause of this?