So if I had sex more than 7 days ago would I be okay to start taking a antibiotic if I dont have anymore sex till 7 days after I finish the antibiotic. I was thinking incase sperm got inside me would I be okay if I waited 7 days after that day to take a antibiotic to make sure the bc pill works right. I take sprintec and my dr prescribed amoxicillin for a upper respiratory infection.