birth control/period

I just finished my first pack of 28 day birth control pills. I'm starting my placebo week today. I started the first day of this pack on the first day of my last period. 
When should I get my period?
I had sex and my boyfriend came in me 2 days ago and I'm low key worried because this is my first time using the pill and have always just used condoms in the past. 
Thanks for the help! 🙏🏼