I Am 49 1/2 Years Old, Suddenly Started Bleeding Without

I am 49 1/2 years old, suddenly started bleeding without stopping. all test are fine, ultra sound etc. always had regulate periods. My GP suggested to take 30 primolut n 5mg TAB for 10 days 3 times a day. Just finished taking them and I am bleeding more then before with headaces? the earliest i can see gyno end of the month. I have a question, what is the meaning of taking the Primolut and then you stop bleeding starts again.