When to see fertility specialist?

Amy
Hello, I'm 35 and my husband is 38. We've been TTC for 4 months now, I just got AF today :(. Im wondering how soon we should see a fertility doctor? I know it can take some time to conceive but it seems like all my friends are having success pretty quickly and I'm just not sure when is the right time to go to a Dr.  
​My average cycle length is 29.7 days, with a follicular phase of 17 and Luteal phase of 12.7.  Do these seem normal legnths? I'm just really frustrated.....