I had sex on the 8th and my boyfriend came in me, I got my period on the 25th-29th, a few hours before I got my period on the 25th my boyfriend came in me again, and then again on the 30th and 31st. It is now the 5th and I've had some nausea, heartburn and been having to pee more frequently then usual. Is it possible that I could be pregnant and experiencing symptoms already?