birth control pill

hey ladies so i just switched my nexplanon to the pill i am not sure how the pill works whatsoever i didn’t have to worry about getting pregnant w my implant ( i have unprotected sex w my boyfriend wouldn’t mind conceiving ) however i started my pill this sunday June 22 and today would make my week of taking them my boyfriend and i had unprotected sex today i’m wondering i guess how it works when is it effective? can i get pregnant right now is there a chance i’m just really confused can someone who has been on it or is on it educate me on what i should expect ??