I had been trying 10 months and told my gp it was 12 months (I knew something was wrong).
I got a referral and the fertility specialist put me on clomid no questions asked but I DID have irregular cycles, late o and short luteal phase so I think he knew I needed it without doing blood tests.
He gave me 3 months on it then will investigate further through ultrasound, testing dh's sperm and HSG if those fail to turn up a culprit. So some doctors will give it up but I would say that clomid has had some pretty full on side effects for me, including headaches, wild mood swings, extreme anxiety and nausea.
It's no silver bullet but I understand wanting it for your sway.