Questions about seeking fertility help for the first time

Longer post but REALLY need some helpful advice:

Me and my husband have been TTC for 5 months with nothing to show but BFNs. We have been using opk's and pre-seed ritually every month. We are both 25 years old and in good health as far as we know and I ovulate regularly each cycle between 15 -17 days. My periods are regular every 30 days and last about 3 to 4 days. My husband has no problem "producing a sample" and we BD when were supposed to according to Glow and opk's. So 5 months have came and passed while doing everything that we can to ensure that it happens and still there has been nothing. At this point I'm becoming very discouraged and broken hearted and I don't know what the problem could be.

My question is at what point do you go to your OBGYN and I asked for some additional testing and help? Because if there is something treatable than I would like to treat it as soon as possible (obviously) and possibly ask for semenalysis for my husband.

So at what point you make that appointment with your doctor and is there anything specifically to ask her to test for or questions that I should bring up? Thanks in advance guys ❤