Early miscarriage??

I am on a 29-30 day cycle, last AF was 2/5/15. My husband and I had sex towards the end of my ovulation window, and about the time I should have had AF symptoms I started having sore nipples, nausea, bad indigestion, and extremely tired. 3/2/15 I started spotting and it was super super light. Then started getting heavier w/ small clots. I had only 1 test come back positive but nothing since. I was suppose to start my period today (I am still bleeding since Monday) and now have the sore breast and mood swings and cramming, but AF is getting lighter now. I have never had spotting before, nor have I had AF come 6 days early. I'm so confused. Any ideas from anyone??