Faint positive follow by bleeding

Sa

I took a test monday-positive

Took another yesterday-negative

Today-bleeding

We had unprotected sex in june several time. Both com several time also.

Last month my period was short not sure of it was an effect from coming off the depo or implantation.

Glow prediction of my period was correct (started yesterday) I'm wondering wtf causes a postitive test to turn negative then to trigger bleeding. Was my faint positive test incorrect?