That happened to my cousin when she was a baby and to a child's friend of mine. The mothers were both nursing and at the same time taking the pills. Pills are not good at all. They both had problems with enamal, they both had broken or twisted teeth and also their color were gray. Their docs recommended to leave it alone because the permanent teeth are the one they have to take care of. My cousin is now grown up and have the most beautiful teeth you can imagine.
I hope this helps you