So confused

I’m 35 and I’ve had regular periods since I started having one at 14. This month however I felt like I could be pregnant (I have three kids already) so I tested early and got two faint positives but then AF showed up. Here is where I’m very confused. It only lasted two days and it was unlike any period I’ve ever had. It was mostly pink with the occasional smear of red. I have never had this happen before. I’m always a five day long period starting off super heavy and tapering down starting on the third day.

I took another test Friday, not thinking I did it midday so it wasn’t FMU. It showed negative.

I’m so confused.