How long to TTC before getting medical help?

Me and my hubby have been TTC for about a year now. We've only tried tracking my period and guessing ovulation. 
I'm getting discouraged and anxious and kind of bitchy. I seem to want a second child more than he. 
I would like some help but not sure if it's been long enough for us trying on our own. 
How long have you waited before seeking medical help?