Please help me quick! I'm worried

Look I don't know if I am being stupid but a few nights ago my friend and I ended up fooling around together in bed. I feel weird saying this but I can't ask anyone else well.
I was touching him and he came and it got on my top a bit and my hand and he was also touching me at the same time. We were lting side by side in bed at the time. We pretty much had all our clothes on like too, but, I'm just really afraid that some of it could have gotten into me. He went to the loo after for a tissue, but, then I slept in the bed too. I'm just really nervous like. We were both a bit drunk too, so weren't thinking the most carefuly!
I'm just really worried, what so you think the chances are that I could be pregnant? Its 2 weeks since I last had my period too, does this mean that my cycle is good for getting pregnant?
I have a pain in my tummy too, but, I dont know if this is from worry or what
Please God I hope I'm not! I can't concentrate on anything after being so silly!
Thanks for help