Could I be pregnant? Pls help!

Hi. I’m 17….
Well I just had my period 2 weeks ago and it lasted one whole week. It was from the fri 29th to at least Friday the 5th. I mean it got light towrds the end but idk. Well I had unpretected sex the night after my period started. And then he “came” in me he said. Since then Iv noticed that I’m eating a little more. My breast got a little bigger, and so did my waist. I feel small cramps. Usually in the morning. It goes on like my stomach was growling. But it’s not. It’s like gas pains or something. Now I’m starting to feel sick to my stomach a couple times a day like in the morning and at night. But it’s not to where I actually need to throw up. Kinda like I need to though.
So i really really really need to know if I’m likely to be pregnant cause I’m kinda freaking out.
P.S. Do you think it’s all in my head?