Okay so... Last month I had sex on the 2nd and got my period on the 10th. It was different though. It was so light I didn't even need a pad or tamp and it lasted shorter than usual and this is gross but it was like a different color. Even after my period was over I was cramping, bloated, had lower back pain, and just recently nausea. All that lasted for about a month and is still here. BUT I just started my period for this month so I was just wondering if I could be pregnant? I would think it was like implantation bleeding but it's been 4 weeks so that's too late right.?