Hi There, My Finace And I Are TTC And Were

Hi there, my finace and I are TTC and were just wondering, when the best time to have sex is ( every day, every 2 days, ect) there are so many different answers! We are going to be starting our second round of Clomid tomorrow, and last time I ovulated on the first try on day 13. BUT the ultrasound lady didn't say i ovulated so we were having sex every other day and that day I ovulated we didn't.. I don't want to miss it this time, even though i know sperm lives for 3-5 days. Any help would be appreciated! Sincerely, TTC couple :)