I had unprotected sex on the 3rd of this month; but I didn't think there was any semen that entered my you know what but I took the plan b less than an hour afterwards. Two days later I had mild cramps on my left side like normal. A week later I took a pregnancy test and it came out negative. I had cramps again a week later on my right side (this Wednesday).  Slight brown discharge this last Tuesday. I took another pregnancy test yesterday the 16th and it came out negative. I'm scared that I may be pregnant but could I just be worried? Pleas help