Missed period

Patient: Hi, i had unprotected sex with my bf around the starting of march.my normal period date is around 22 to 25 of every month.last month i had my period around 22 of feb.altough he pulled out before ejaculation. we are nst ready for the baby.pls sujest. what should we do. and even if i have a faint line on pregnancy test srtip.should i go for the pills??