When should I go to the doctor?

I'm in CD11 of cycle 11. I've been ttc for 11 long, tiring months. I know 11 months is nothing compared to all the women who have been ttc for years, but it's starting to bring me down. I read that it take 50% of couples to conceive writhin the first 6 months of trying and 80% for couples who have been trying for a year. It will be a year for me next cycle if I don't get my bfp next month and i was wondering if that should be when I consult a doctor. It's getting me down. One minute I'm super excited and enjoy ttc but other times I begin to get so impatient it almost actually hurts. There is nothing me and DB want more than a baby and I just feel like we are so unsuccessful. Any thoughts?