A New Story?

For the first time in long time, I am actually having the beginnings of a new story form in my head. I am thinking about trying a new genre. I've always stuck to fantasy set in a medieval time. I am not entirely sure yet, but I'm thinking maybe a mystery or thriller set in modern times. I feel like its time to branch out a bit. Its probably all a moot point. I'll probably get writers block and give up after the first few pages. But I'm going to keep trying.