Has anyone ever gotten negatives on the cheap $.88 cent or $1 test but very light positives on first response?

I had a miscarriage/D&E on May 16th of this year. I ovulated on June 12th. I started taken test 2 days ago an I ended up with faint positives on the first responses but negatives on the cheap test. The lines were before the time frame. I also took a first response digital an it has a yes + but still has the clock symbol so I believe that it could be invalid results.

I haven’t had any bloodwork to show if my levels had dropped just negative pregnancy test around May 30th. I’m going in on Wednesday to see what is going on.

Could it be left over HCG from my loss an the first response is just sensitive enough to detect it or could it be a new pregnancy?

*I have not had a period in between. *