Threatened Abortion?

So I went to the doctor Monday and had blood drawn to see if I was pregnant, since I had been getting faint positive pregnancy tests. They called me Tuesday and said no that my hcg was too low. That was it. I then went online to look at my documents and it said “Problems: Threatened Abortion.” I emailed my doctor and asked what that meant and he said “it’s what they say when someone has positive tests but has cramps, bleeding, etc.” I never told them I was cramping though? I also haven’t had any bleeding. So was I pregnant to begin with then?? Why wouldn’t they tell me that information when they called with the results? I’m just so confused!