I am on depro-provera now for over two years and I still feel like conceiving is this normal?

I am 34 and still feel that urge to getting pregnant. It is like my mind says no and my body says yes. I am on a very high dose. the usual dose is 150 but I have to take 200-250 to stop the ovulation. Plus it has help with my depression and sever mood swings. If I was to get off of it what is the chance of miscarry and Wow it really hurts when the with drawl comes woe. I feel like a teenage girl starting her cycle for the first time. I also wanted to ask other females how they liked the birth control. I love it because I have seized my periods and it controls my mood swings.