We tried for #2 for nearly 4 years. We gave up and decided the best thing was for me to get healthy again. I lost a lot of inches (the scale didn't move, but I went down 3 sizes!) and changed my diet using a personal trainer. I had some major hormone issues going on, although I was only 27. I started seeing a naturopath & discovered I was menopausal and had all sorts of other issues going on. Within 4 months of seeing her the first time, we were pg w/#2!
The joke is she fixed me too well b/c now I'm pg w/#3 who is due just 2 weeks before #2's 1st bday!! This one was a major shock as we thought we were done, but as it gets closer we're getting more excited (1 month to go!).
Obviously there were a lot of factors for me, and who knows which one specifically made the difference. As the pp already said, there are so many factors that can affect TTC. Just want you to know I've been in your shoes and totally understand. We got through it and were able to conceive.
All 3 of our kiddos were surprises. With #1 we tried for 9 mos & gave up because the timing was awful anyway and we decided we really weren't ready. We tried for so long for #2, and then #3 came right after. In all 3 pregnancies, we'd given up and accepted what we had and then it just happened.