Serious Provera Question.

I was put on Provera to bring on a period since i hadn't had one in almost a year due to being on birth control and wanted to start trying to conceive. I didn't know much about it when the Dr prescribed it and didn't think to ask about the safety of it at my visit. I'm told to take it for ten days every month starting on the 20th. But it would be too early to know if I was pregnant each month by then and I am worried if I do get pregnant the effects it will have on my baby.