Chemical?

I had a miscarriage back in April. On Sunday, AF was supposed to come but it didn’t. Took a test in the evening and it came back a VVFL on a dollar test cheapie. To put my mind at ease I got a FRER and it came out a faint line. Thought that was weird because other times I’ve taken the test by the time my period was supposed to come. It wouldn’t be faint. It definitely would be positive. Well today, it looks like my period is here. I’m confused could it be a chemical pregnancy?