pregnant or not pregnant?

My husband and I are trying to conceive. We were intimate the day of ovulation. Its been 6 weeks and a half. Yet I don't know if I'm pregnant. I'm incredibly tired. I go to the bathroom frequently. I gained 5lbs in a week already. My breast are slightly sore. But I started bleeding pretty light during my 4th week. I thought I got my period. It wasn't heavy at all. It went on for 6 days. Towards the last couple of days it was on and off. 3/4 days ago I was bleeding when my husband and I finished being intimate. It was a brownish color and light. I spotted a bit and it was gone. I took 4 home pregnancy test and they came out negative. I need some help! ????