Faint positive still there

I was getting faint positives that where getting darker ... obviously darker there was no doubt in my mind I was pregnant. I waited a couple days to test again and that morning I started my period .. a day early I might add I new what had happened I’ve been here before I took a test anyway the line was still visible but very much lighter almost gone (fears confirmed) now this was 5days ago my period is about over so I took another test (just what I do to 100% confirm negative) there’s still a very faint positive is this residual some how? I’ve never had this happen

P.s. yes it was a very heavy full blown period