This is Kay of KC and I was taking 400 mg. of Doxycycline for one full year with Mycobutin (Oral form of Rifampin) and my teeth actually had black etching from the surface. Rest assured, a good cleaning and some white strips, back to normal.
I panicked too, but if you can hang in there, try to.
PS. I am now treating the Babesia with Mepron, yellow paintball like liquid suspension and now they're yellow!