I got my period late on 1/16/19. It lasted about three days and was very light (unusual for me). It will be 2 weeks now and I have been feeling nauseous for the past couple days and today I’m getting tightness and cramps in my lower abdomen. I’ve also been very tired. Me and my boyfriend had unprotected sex before I got this unusual period and he ejaculated inside me. Should I be concerned about being pregnant?