I had my last period around dec. 11-14. I had unprotected sex on the 16th.. I was supposed to have my period Jan 7th-11 and it never showed up, on the 10th I experienced a day of brown blood (the kind on your last day of your period). It has now been over a week and I still haven't received my period. No signs have showed up, the only one is being hungry, but I'm an athete and training for the 3k 5k and 10k. I was under a lot of stress due to the fact of maybe being pregnant after the night it happened. I'm not sure what I should do?

Buy a pregnancy test.