My period won't stop and trying to have a baby at the same time?

I am 29 with two kids 9year girl and 4 year old. I've been trying to get pregnant and can not. I just went for an appointment at my local clinic and told them that I have been spotting blood, like a period since March and told them I wanted it to stop. I was stold that since I wanted to get pregnant that they would not give me any birth control. My question is how can I get pregnant if I still bleed? What can I do?