Pregnancy after a miscarriage

I took a pregnancy test on Wednesday that one came up positive w a very faint line, then like 2 days later I look at it, and the line is gone, today, I took another one and that came up positive w another faint line. Are these invalids or false positives? Or from my miscarriage. Bc I haven’t gotten my period yet after I miscarried and I was ovulating, awhile back.