Low sperm count

So me and the DH had his first baby 2 years ago within our second month trying was so easy no opks no pre seed we only used the glow app to see most fertile days now we are trying for our last baby his #2 my #5 we did a sperm check fertility at home test and his came up negative saying low sperm count we are using opk preseed and I just ordered his 5 different vitamins to help with sperm count we are both in our early to mid 30s I’m 33 and he is 34 time is not on our side being after I’m 35 my chances of getting pregnant is a lot lower and also a higher chance of birth defects due to age I’m just hoping to have one more and it is heart breaking to find out low sperm count I’m hoping it is wrong