Why am I getting faint positives on my period?

Has anyone else noticed there period just wasn’t the same (a lot lighter) but still red blood so decided to take a test? Well I started what I thought was my period yesterday with pink discharge today I have a light flow of red blood however I’ve had 2 faint positive tests? What could this be? Has anyone else experienced this? I’ve had 2 chemical pregnancies previously and both times all tests was negative when I started bleeding