I'm 36 using the Ubiquinol form of coq10, 400mgx2/day for 2 months and I pair it with Vitamin E which I was told would help absorption. It's supposed to decrease egg abnormalities, decreasing risk of miscarriage, prevent downs and other developmental problems. So not sure if you'll get a BFP result soley based on CoQ10 but there is a study showing that it improves egg quality https://drewnesbitt.ca/coq10-fertility-super-supplement/
i suppose if the egg is good it's more likely to fully develop into a baby so it's really worth a try!