I had sex while I was ovulating this month and didn't experience any weird symptoms at all. But my "period" came 4 days early making me have two in one month and it was on and off spotting. I never filled a tampon or pad. So much so that I was worried about toxic shock. I went to donate plasma and when they gave me my physical, I had gained 7 lbs in less than a week and my heart rate was a 111. So they sent me home. Ive 4 tests since then and they have all been negative. But I've been cramping and getting back pain since that day. And I've been really tired. Is there a possibility that I am pregnant despite negative tests? Please help!!!