I dunno it could be a number of things including pregnancy, you will prob just have to wait until your period is due and if it's late take a hpt as soon as you get up in the morning so your urine wont be diluted.
My last period was OCt 28< and I had unprotected sex on Nov 6. I have never had sore boobs before!
You can't really go by that...have you had your period?
It could be a sign, but I recommend you take a test. That will tell you for sure!