So I got my period on Friday at 9:45 pm and started taking my lo Loestrin fe Saturday at 9:00. It says it’s immediately effective when you take it within the first 24 hours of your first period. I had unprotected sex three times on Monday night, all three times my boyfriend finished inside of me. I was still on my period with little blood, but I’m just nervous. I’ve been taking the pills exactly as I should be and will continue to.