Tested positive then neg. Does this look like a miscarrige?

This month I got a positive pregnancy test once my period was 4 days late. It was pretty dark. The next morning, I still had the line but it was fainter. The lines started getting lighter and lighter until there was nothing and then I started bleeding.

It wasn't like a normal period. Sorry for the TMI but there was little brownish dots and tiny string looking pieces. Like little crescent moon shaped. The bleeding lasted 4 days.

I heard chemical pregnancies don't make your period late. By the time I started bleeding, I was a week late.

My previous cycle came 5 days early. It was a regular period. Not heavy but not super light. I don't know if my timing was off.

When does chemical pregnancies occur? And I heard they are supposed to be like a "normal period" but this wasn't. It was mostly brown with one day of red.