Could I be preg?

It lasted 10 secs. maximum and he pulled out about a minute before he ejaculated. 2 weeks later, I got my period on time, it was heavy and lasted 6 days. However, I've heard you can get your period while preg. The only "symptom" I'm getting is frequent urination, and I'm not sure if it has to do with pregnancy. Could I be preg?