Sex when ovulating

Kim • Married to wonderful husband. TTC 3 years now.
Do most people have sex once a day or every other day or twice a day during ovulation? Would sperm count go down with doing twice a day like morning and night? We have been doing once a day with no luck. Have been trying for 3 years. Have been to a handful of doctors and they say I'm completely normal. My husband has a son already who is turning 11. Should he get his sperm tested? Started ovulating today so I'm crossing my fingers!