Unprotected sex and possible symptoms?! No clue!

Kay guys. Here's a real thinker for you.
On October 27th, I had unprotected sex twice...and then again the next weekend, and one more time last weekend.
I didn't really think anything of it because with guys before, I have always shown signs of being sterile.
Well as of the past week, I've been extremely tired and have had these stomach cramps from heck. They're not lower abdomen cramps, they're kind of in the middle...and they make me a bit sick to my stomach, but not too much.
I have a slight fever right now (99.7º), also.
My period is 2 days late, as of today...and I'm not really freaking out, I just would like help.

I don't know if those could be really early symptoms or anything. Does anyone have any ideas? If my period doesn't come by the next week, I'll get a test, but I just want some feedback about these "symptoms".
Thanks!~