Faint Positive or Ghost Line?

I had a D&C on March 17 because at our 10 week appt, baby had no heart beat. I haven't started my period yet, I did ovulate already on the 2nd of April verified by home tests. Now a string of 4 First Response tests have had a very faint positive. My mind wonders if I still have HCG in my system from miscarriage but heard you can't ovulate unless your levels go back to zero. Or am I really pregnant again :/​​