I'm 18. Had unprotected sex two days before my period. Had strange brown discharge at the tail end of my period. I'm moody, nauseaus, tired, sensitive to smells, constipated, peeing more. I don't have breast tenderness, fainting, weight gain or much cramping. This was two weeks ago, so it's early for a pregancy test. Any thoughts or ideas on whether or not I could be? seems like i have about a 50/50 chance right now.