Hubby On Midnights

Okay, I'm 30, stay at home wife, hubby is 31, police officer and works midnight to eight am. We have been married and actively TTC #1 since we got married June 30, 2012. I just can't figure out what we are doing wrong?? Although it is rather hard for us to BD because of the shift he is on. We have tried baby making vacations, I did the BBT thing for a while. I think we just aren't hitting my "O" day just right. That has to be it. There is nothing physically wrong with me that I know of that could explain the infertility. I've never been on birth control, never really had the need for it lol. Maybe there are other LEO wives or wives with hubby's on midnight shifts that are having difficulties as well? I'm thinking maybe I just needed to vent a little. This has been a very frustrating 12+ months.