unprotected sex, possible pregnancy?

me and my boyfriend just recently had sex on the 18th of this month, it was my first time. it was protected but before that, on other days, we did do other things. alot of dry humping. At one point i was only in my underwear and he was in his boxers and we were both wet. Also a few days before actually having sex we took a shower together and at a point he picked me up and stuck it in for a little bit, i'm not sure if it went all the way in but i complained of the pain and he took it out and he was wet. which i know was pre-cum. Now a week or two after the shower i'm starting to feel strange. i have stomach cramps not extremely bad but mellow. i'm always tired now, almost sluggish and i have body pains. like back and sides and such. my hormones seem to be out of wack to, different then it normally is. So please any advice or suggestions or even ideas would help greatly. please and thank you.