Hi B.
A long story short, my husband and I tried to get pregnant for over 2 years (we started trying around 7 years ago), after 2 years of trying without any success, we decided to seek help from an infertility doctor. It then took an additional 3 years before I got pregnant with my first baby (7 or 8 attempts with IUI and 2 attempts with IVF). After I got my regular period back, we decided to try for the second one (I wasn't getting any younger) but after 8 months of trying (and at this point in life with absolutely no romance left in our lives due to the many failed-on-command-attempts), I decided to go back to the infertility doctor. Since this was for the second child, the infertility doctor decided to follow the exact same process as with our first child and I got pregnant in the first IVF attempt.
I guess the bottom line is how long are you willing to wait before you become pregnant with your second child ? Just keep in mind that just because you get professional help, there is not guarantee that you will become pregnant right away either. Things (can) take time. Personally, I just wish I would have arrived at the conclusion to seek help earlier so I would not be having my second child at age 38 and we would not have lost all romance in the process.
If you have decent health insurance, why not at least talk to an infertility doctor and let them at least run some of the initial tests on both you and your husband to determine whether all your attempts are in vain (due to medical reasons) or if you just need to "be patient".
Good luck with everything. I really hope your wish for a second child will come true soon for you.
BR,
K.