This isn't an exercise in being smug but a sincere hope it might help anyone who is in a similar situation. MN has been a massive help to me...
I have a gorgeous DS who was conceived easily when I was 37. I knew I wanted another DC and AF returned around 8mths after birth and I stopped B-fing at 10mths as DS wasn't taking much anyway. Plus I knew I had to crack on, given my age.
A long story shorter, I suspected summat was amiss after about 6 months of TTC and tried to get help from NHS. I was told to have SWI EOD and all should be fine. A few months passed. Returned again. A young female GP suggested that my egg quality was probably the issue and should go private for AMH tests. Never a mention of my partner's health/fertility.
Private tests - full MOT - revealed all pretty healthy. AMH level quite good for my age.
1 year at least of TTC - I finally persuaded DP to get tested so we could rule him out as an issue and I could stop nagging him to give up his moderate but daily drinking. Lo and behold - very poor semen analysis results.
DP did give up drinking and we had weekly acupuncture. Three months later - a BFP, despite my age. Of course, there's a long road ahead but even so, we've finally managed it.
Best advice I had from here - a very helpful MNer - DON'T dtd EOD but hold off at least a week before Ov to get better quality swimmers. I'm sure this along with the lifestyle changes really helped.
Wishing all of you the very, very best and don't be disheartened or fobbed off by professionals who - despite good intentions, I'm sure - can never really know your personal circumstances etc.