Me & my bf have sex everyday, or every other day. can that lower his sperm count? how often should we have sex if ttc? how do we know his sperm count?

You would need: A semen analysis. It can take 48-72 hours for a full sperm count to add up. Regardless, having sex every day should not lower your chances of becomming pregnant. Sperm lives 7 days inside the uterus so there is likely a steady flow in. I would say if you are having issues with getting pregnant, which is 1 year of unprotected sex, then modify. Until then go with it ... That's what i'd say.