Help?

Jesse • 25 years old TTC baby #1 w/PCOS for 3.5 years ~2 failed IUIs~
How long after ttc to talk to a doctor? After the 10 month mark I saw one and he gave me a pelvic exam and told me everything was fine. He said to come back if my period didn't start in two months. I waited 3 months and it did start but, 5 months later still not pregnant and my period is irregular. What's the next step in determining why I can't conceive.