Help, Could I be Pregnant?

I had a medical abortion March 24th, I was 5w 5d. After I was cleared to have sex I started birth control and having sex, we used condoms for the first week, but after that nothing. I've been having pregnancy symptoms again such as cramps and fatigue and just yesterday I went back to the doctor and I was still "faintly" pregnant, after the ultrasound showed that I had no retained tissue.