TTC 6 Months - Advice?

My husband and I have been trying to conceive for 6 months and no luck. I have been using opks to track ovulation. We have a healthy 1-year-old and we got pregnant with him after 3 months of trying. If I go to my OBGYN, do you think she will be willing to run some simple tests to make sure my levels are normal? I realize that many couple try for over 6 months, but I don’t want to continue waiting to later find out that there’s a problem that would have been easy to fix. TIA!