I had unprotected sex a little over a month ago. I began having severe cramps, ankle pains, night time nausea, major bloating, cravings and tender breasts. I took a cheap pregnancy test after I realized my period was three or four days late. It came back negative. It turned into a positive after an hour. I took a first response test and it came back negative. The next day I had spotting then very suddenly a heavy flow with clots. Could I have had a miscarriage?