My doctor put me on .05mg once a day. On the third day I started bleeding. Is that normal?

On my third day of taking prempro 0.625/2.5 mg I started to bleed. I bled for 15 days. Its now been almost 2 months and I have not bled again. Now ,I found out from an aquaitance that you won't get a period while taking prempro. It would have been nice if the doc would have exlpained this to me. Needless to say, I wont be going back to her!!