I had unprotected sex with my boyfriend on May 19 and 21. I was very lightly bleeding after the 21st and now I get constant headaches, feel really bloated, been cramping, have nausea, backaches, mood swings, feeling tired all the time, and getting hot easily. I noticed that my breasts have gotten bigger and I feel uncomfortable all the time now. Could I possibly be pregnant? I took a test that came back negative but it could still be too early to tell. Any help would be greatly appreciated.