How secure is progesterone tablets as fertility treatment for PCOS?

I have be diagnosed with PCOS and my doctor enjoy started me on a course of progesterone tablets (5days) to make me bleed. On afternoon 2 of the bleed I will start taking Chlomofid to make me ovulate.
I asked if this be safe and what if I be already pregnant. She said that none of these drugs would affect a pregancy. Is this true and what would happen if I be pregnant, would I still get a bleed?
Christina yes thats true but i dnt devise youl still bleed-so dont worry