Feeling frustrated.

My husband & I have been TTC since January with no luck. One of my closest friends started trying in June & I just found out she is 13 weeks pregnant, with TWINS!!! I'm so happy for her, but I am emotional. I teared up when I found out. My husband & I work oppsite shifts & Idk if we just aren't having sex at the right times or if there is something more. My dr. said I don't have PCOS, but she said it appears I don't ovulate regularly. I'm not sure if I do or not, but have taken ovulation tests 2 different months & got + for ovulation around the time I should be ovulating.

*sigh* I guess I don't really have a question. I just wanted to vent my frustrations.