Is this a chemical?

Carina❣️ • Keoni & Ezran 💕🌎

I had got 2 faint positive tests a couple days ago & my period was due feb 13th. This morning I started bleeding so I took another test & it was negative.. if this is a chemical how long does the bleeding last? When will my period come? Can I use tampons or only pads? & Should I make a doctors appointment still?