My first pregnancy ended in m/c at 7 weeks. I waited until I had one period after the m/c. Then we tried and got pregnant with DS1 the very next cycle.
I lost another pregancy in 3/08. We waited a couple of cycles to try again after that loss. This is my 4th cycle of trying but we're doing TBM O+12 so I'd expect it to take longer.
Good luck to you. I'm sorry you went through a loss too.