It really depends on your personal situation. I would recommend calling the sex sense line on 1-800-739-7367 or 604-731-7803 and discussing your situation. All your information is confidential and they would be able to discuss your options with you. It seems like you may need a pregnancy test or some emergency contraception.
Many clinics and pharmacies can provide the emergency contraceptive pill (morning after pill) up to 5 days after someone had unprotected sex.
There are also other emergency contraceptive methods that can be used in BC Canada to prevent pregnancy. Have a look at the Options for Sexual Health Emergency Contraception Fact Sheet for additional methods.
If someone is already pregnant there are a few options available to stop this. Willows Women’s Clinic in Vancouver offers surgical and medical abortions. Have a look at their information page on Choosing Between surgical and medical abortions for additional information about these procedures.
Let us know if you have any more questions or concerns.