Help! I had unprotected sex right before my period was meant to start. My period is heavy and long but this time it was short( 2 days) and light/brown in color . I took a test 4 days ago (2 weeks after we had sex)  and it said negative. But I've been feeling SUPER tired and queazy and moody like I'm pmsing but I'm not usually able to nap or moody. So Is it even possible to get pregnant then and what should I do now?