Miscarriage

I started what I thought was my period on May 14 and it lasted through the 18. I stopped for a day or so, and then started bleeding again. Bleeding was light so I took a pregnancy test to rule out the possibility. The rest came back positive, and so did the next 12! Then the 13-15 tests were negative, which I believe is a miscarriage or a chemical pregnancy. I started bleeding again today, and passed two small clots. Is it normal to still be bleeding? Is my body just confused? Any help is appreciated.