Weeks at miscarriage?

How many weeks along were you when you miscarried? I'll be 36 in a month and am almost six weeks pregnant with my first on my first try! I'm so nervous about miscarrying because we got pregnant so easily—like I feel something's bound to happen. I got my BFP at just over three weeks, and each week I feel I hit some sort of milestone. If you miscarried, what week were you in? Am I out of the woods more once I hit 12? I think because I'm older I'm just really nervous, and my doctor's appointment isn't until 9 weeks.