A little history...my last period was very light almost more like spotting vrs. bleeding. I had a blood test done and I was not pregnant. Then I had unprotected sex around the time of ovulation. The past week I've been feeling that my period is coming but I've been experencing more cramping than normal and my breasts have been hurting more than usual. I had a very little brown discharge once after I went to the restroom but my period still hasn't started. Other than that I've been very very dry down there. I have also been experencing heartburn, which I usually don't get. What is going on...I'm concerned that I won't have a period again...any advice would be great!

I had an ultra sound last week and my ovaries looked fine but there was some build up in my uterius. Most likely cuz I didn't really bleed last month. Would the ultra sound of shown a 2 week pregnancy?