Think I’m out this month

I’m 40 and ttc my 4th (yikes!). Our youngest child is now 7 and after a lot of decision making my husband and I decided to try for one more child. This is month 2 and I’m 10 dpo but getting negative tests on FRER. I also have chronic kidney disease, and my urine is always dilute, even early morning. I said I’d give it 6 months but then people would think I was too old and laugh at me (or so my head tells me). I look at posts on here and so many are half my age. We always conceived very quickly before, am I being unrealistic to think that’d be the case again? Am I crazy even trying? The heartbreak with every negative test...I’m not sure men understand that