…… Am I covered? Was that a week or would Thursday have been a week?
You are right, all hormonal forms of birth control, including the Depo Shot take 1 week before they are effective. So, to reduce the risk of pregnancy someone should use a back up method (like abstinence, or condoms) for 1 week.
Since unprotected sex did occur on the 1 week and not after, there would be a risk of pregnancy. Emergency Contraception is an option, which can be taken up to 5 days after and is more effective the sooner it is taken. Emergency Contraception works by delaying ovulation- when the egg is released from the ovary.
After the initial shot, Depo is up to 99% effective as long as someone is getting their shots on time, every 3 months. Remember, the Depo Shot does not reduce the risk of STIs. Only condoms and dental dams can do this.
If you have more questions or want to make an appointment at Teen Clinic give us a call at 303-442-5160