I am 38 and DH is 40. We have been trying to conceive for about 2 years and then went to the fertility specialist. Our diagnoisis is male factor - there are plenty of them and they can swim just fine but they have a morphology issue so they can't penetrate the eggs. There doesn't appear to be any problem with me (for my age). So, we are having to go straight to IVF with ICSI to help get the sperm inside the eggs. This is our first cycle coming up.
So, you are definitely not alone at age 37! Good luck.