I had anal sex last month 2 weeks after my period, and I have yet to get my period this month. It was early last month, could it just be late this month? Am I pregnant? Please help: I'm so worried.

Hi, Taylor.

Just so that this is clear, for you and plenty of other people who have been in the same spot, here is what anal sex is and is NOT:

• Anal sex is not a method of birth control. While vaginal intercourse presents a much higher risk of pregnancy, unprotected anal sex can also present pregnancy risks. During sex, when we're all aroused, things usually get mightily slippery down there. So, if you're a receptive partner to anal sex, when your partner ejaculates, that ejaculate will run out of the anus, and sometimes can easily slide down the perineum to the vaginal opening. That can create a pregnancy.

• Anal sex is not safer sex. In fact, anal sex is just as risky when it comes to sexually transmitted infections and diseases as vaginal sex, and also presents greater risks of bacterial infections (even among partners who have both had full STI screens with negative results).

• Anal sex IS sex. I don't know if this is the case for you, but a lot of young women come here reporting this is the case for them -- that anal sex isn't "real" sex, or isn't really sex -- or what their male partners have told them, so just in case: anal sex is sex. Just as much as vaginal sex. It carries risks just as high, physically and emotionally, and is "real" sex. So in the case you're having anal sex to try and preserve virginity or because you're not feeling ready for "real" sex, please understand that that's flawed. Anal sex IS "real" sex, and if you don't feel ready -- emotionally, physically, or both of you are not ready to manage it responsibly -- for sex, then it's not smart to be having anal sex.

If you're going to engage in anal sex, you have got to be using a condom, and it really is that simple. Should you and your partner have already had six months of sex with latex barriers consistently, six months of sexual monogamy AND at least two full and clear STI tests in that period of time, then while bacterial infection risks still exist, other STI risks are decreased. However, if you're not using another method of birth control, pregnancy risks may still exist.

If your periods are not yet regular, then it's possible you're just dealing with some irregularity. However, since you did engage in an activity with a pregnancy risk, and your period is late, I'd suggest you take a pregnancy test now. In the case you did become pregnant, that's something you need to know as soon as possible so that you have time to fully consider all of your options and make whatever decision is best for you. You'll also want to schedule a full STI screening in about a month for yourself (and your partner should have one, too).

For future reference, if you had this sex with a regular male partner, I'd suggest having a talk to make clear that unprotected sex isn't okay for you to do until you're ready to be pregnant, and he's ready for you to be pregnant as well. I'd make clear this presents STI and pregnancy risks, and that if you both do still want to do it because it's something you enjoy, then you need to get set up to be doing it safely, okay?

Just so you have these for your reference:

• Ready or Not? The Scarleteen Sex Readiness Checklist
• Safe, Sound & Sexy: A Safer Sex How-To
• STI Risk Assessment: The Cliff's Notes
• Where DID I Come From? A Refresher Course in Human Reproduction
• Condom Basics: A User's Manual