hi, i think it really depends on what kinda of miscarriage you had and how it ended.
When I started ttc, i got pregnant within 43 days after my last birth control pill, so really fast. but that ended up as a missed miscarriage and I had to go in for a dnc and allow my uterine lining to heal. The embryo had also implanted abnormally, leaving my uterus wall at a very critical 3mm thin. So after the dnc, the doctor did mention that due to my condition, i should wait 3 months before trying, because the chances of a miscarriage again is very high. So I waited about 3-4 months, we did try in one cycle but no luck, but now, exactly 15 weeks after my dnc, I'm pregnant again and this one looks really good. I got my BFP much earlier than with the previous pregnancy. With my previous pregnancy, I had nightmares every night about losing it and it did happen. But with this one, I am taking it very relaxed and no worries at all, no more nightmares thank goodness!
but then again, the chances of miscarrying increases drastically after you hit 35 years, so maybe go and see a doctor to find out the cause. Good luck and fx-ed for you bfp!