Pregnancy Scare or Is it real

So my boyfriend and I have been together for 6 months. 2 weeks ago we got a little to out of hand. We started taking off clothes and he only stuck the tip in but for like 1 second. He only pre came, but it wasn't bad enough for us to feel anything else. Now I'm having tender breasts, Dizziness, Lightheaded, Drowsy, Stomach Aches, and I threw up this morning. Is this just my period coming or am I really pregnant?