I miscarried in mid-August last year and was pregnant again January this year. We hadn't been DTD until November/December as I just wasn't in a good head space, so really it didn't take us long at all.
No fertility advice sought as it was a short amount of time and we weren't really trying, i.e. happy with or without a baby. As to how long to wait to do that, it probably depends how old you are. Over 35, I'd maybe only wait six months before getting everything checked out. Younger maybe up to 12 months. Depends how keen you are and also how familiar you are with your cycle. I know before the first pregnancy I was way off base in terms of when I was actually ovulating.