““I had unprotected sex last night, the same day I forgot to take my pill. I know that you can use birth control pills as emergency contraception. But I don’t know how much to use. I’m on Yaz, which is low dose so I don’t have as many side effects And, also, my boyfriend was saying he didn’t want me to use it because it causes abortions. I know it doesn’t but I can’t explain why to him. Help me out. Thanks.” –CM

You’ve got good news and bad news coming to you, C.M.
Good News: yes, hormonal birth control pills are often able to double as emergency contraception (also known as EC, the morning after pill, etc)

Bad News: you can’t use Yaz as emergency contraception- for the exact reasons you mentioned: the low dosage of estrogen. Right now there is no approved dosage for it as EC. For a list of correct dosages for the pills for which it does work, check out http://ec.princeton.edu/questions/dose.html#dose for a handy chart. In your case, C.M., it’d be a good idea to go get some EC in advance to keep around in case the need should arise. If you’re under 18 you’ll need a prescription but for legal adults, it’s over the counter, baby.

More Good News: forgetting your pill for one day isn’t really dangerous. Don’t make a habit of it, obviously. But one missed pill doesn’t require EC use. Go ahead and get some Plan B if it’ll make you feel more comfortable; but it probably isn’t necessary.

Your boyfriend seems to have latched on to a bit of folklore started by people who have an axe to grind with contraception in general and spread by those who didn’t get as much out of 10th grade health class as their gym teacher’s might have hoped. Even some radical zealot pharmacists fail to appreciate how it works and refuse to fill ‘scripts. These individuals might benefit from an afternoon of gathering around Miss Timaree’s fun-filled “How Babies are Made” workshop.

For a woman to get pregnant from intercourse you need the following things: ovulation, motile sperm that can reach and penetrate the ovum, and implantation in the cozy uterine den. What birth control pills do: raise either your progestin and/or estrogen levels to the point that the body doesn’t release an egg (it’s under the impression it’s already pregnant due to the hormonal levels), change the cervical mucous to prevent your man’s varsity swim team from getting to the deep end of the pool, and giving the uterus a Spartan remodeling job so there’s no proverbial couch on which the fertilized egg can crash. Without the egg, fertilization and implantation, a pregnancy cannot occur.  Simple as that, boys and girls. Emergency contraception does all those same things, but in a mad hurry, depending on where you are in your cycle.

Here’s the really pivotal fact: If you’re already pregnant when you take EC, the fetus is unaffected. It won’t be aborted and it won’t cause birth defects. If a pregnancy cannot be terminated by EC it is by definition not an abortion. Some people confuse EC with abortion drugs, which are made out of entirely different chemicals that work in a very different fashion.

The reason EC can be taken up to 120 hours after unprotected sex is because it takes a hot minute for the whole implantation process to go down. First the beauteous egg must arise from her nap and put her face on so she can go out and see what all the racket is downstairs. After she makes her way down the fallopian tube for a couple days and meets the sperm, it takes several more days before the happy new couple makes their way to the pad to get to baby making business. So instead of ejecting a several day old fetus, EC is putting up roadblocks at every possible point in the road trip before a fetus is even possible.

Kudos to you for thinking so responsibly, C.M. I hope this was a clear enough explanation of the process for your boyfriend.

Timaree Schmit is a trained sexologist who has also worked as an HIV prevention counselor and sex educator. She has written widely for numerous publications and was recently recognized by Coed Magazine as one of the 10 Most Famous College Sex Columnists in America. Timaree is completing a doctorate in Human Sexuality at Widener University.

Do you have a question or comment? Please email Timaree directly at sexpert@MarcLamontHill.com