How long did you wait ttc after miscarriage?

I had a missed miscarriage in May after finding out at our 12 week scan we'd lost our twins. I had a d&c 4 days later but unfortunately they didn't do a proper job and after 3 weeks of bleeding and positive pregnancy tests I was told I needed another d&c. That was the end of May. I got my first period beginning of July and want to try again but am petrified and just wondered if you ever feel 'ready' or if you just have to bite the bullet and try to be positive next time round??