Pregnancy symptoms? it's like my upper stomach, not my uterus or lower abdomen

Hi, I am on the pill. I take it every day same time. Im responsible. I got my period March 12-15, I had sex with this guy on March 18th, he did not come in me, he was doing me and he pulled out and jacked it for a minute before coming. It is now March 31st, almost two weeks after the sex. My stomach started hurting yesterday (I mean I have been eating a lot lately) and today and im not sure why it's been hurting. And what's weird is it's like my upper stomach, not my uterus or lower abdomen. Could I be pregnant? Or are these stomach pains something else?