Was this a chemical

Trigger warning

Hi! I know this probably isn’t the right group, but maybe I can get some answers. Back in July I think I had a chemical pregnancy but am not sure if that’s the right term, or if maybe it was a different kind of miscarriage. I had what I thought was a period from July 11-15th. Two days later I started bleeding again which is not common for me, so I took a pregnancy test that came back positive immediately. I contacted my OB office and explained that I was bleeding and they told me to call them back after a week if I still had positive test. I did still have a positive test a week later but was still bleeding. During that time I went to a women’s care center and got an ultrasound done, they only saw a thickening of my uterus. My Ob appointment was on August 6th and at that point was no longer having positive test and had <1 hgc in my blood. Do you guys think it was a chemical? A different type of miscarriage?