Pregnancy or menstrual symptoms?

So, I had unprotected sex 6 days ago on my ovulating day, he also came in me. I am supposed to get my period on the 15th. But all last week I felt funny. Completely different than I normally do, i.e. sore and heavy breasts, fatigue and yesterday I had lower stomach pain. I thought it was because I was going to start my menstrual cycle soon, but I don't ever get symptoms 2 weeks early. I usually get them this week. Can anyone make any sense out of why I was feeling this way?