Think you're having safe sex? Think again. You might be at risk even if you're using condoms, taking birth control pills—or even not having intercourse at all.Lauren Streicher, MD, an assistant clinical professor of obstetrics and gynecology at Northwestern University’s Feinberg School of Medicine, issues nine safe sex reminders.Anal Instead of Vaginal Quite a few Cosmo girls have told us they're not into anal, but for any ladies who try to avoid pregnancy by having anal sex: If you're not using a condom, you're still leaving yourself open to STDs. (So, use a condom.)Pull and Pray Pulling out when he ejaculates to be extra careful? There's sperm in the pre-ejaculate that slips out of his member and into your vagina during sex, so you can still get pregnant. Not to mention, if his sperm is deposited right outside your vagina, those sperm can swim and still cause pregnancy. Best to use a condom regardless.You Got Tested You and your man claim you've been "tested for everything," but different doctors test for different STDs, so make sure you know what you're actually been scanned for. For example, Dr. Streicher's battery scans for gonorreah, chlamydia, hepatitis, HIV, herpes and syphilis, but not all docs are as comprehensive.He's a Virgin Even if you don't have sex with a guy, and even if he's a virgin, he can still give you HPV. The virus (which can give you genital warts or cervical cancer) is spread through skin-to-skin contact, not semen, so if he's been naked and rubbed his penis against another woman's vagina during a hookup, he can pass it to you the same way. (Unfortunately there's no way to test a dude for HPV.)To Shot Or Not Consult your personal doctor, but if you're under 26, Dr. Streicher says the best way of protecting against HPV is to get vaccinated.Double Bagging Some women think, "Two condoms: I'm doubly safe!" But double bagging is the worst thing you can do. Two lubricated condoms get slippery against each other and can fall off, depositing sperm inside you—and leaving you open to contracting an STD.Tinkle, Tinkle The best way to prevent against a UTI (urinary tract infection) is to pee after sex. Intercourse can irritate your bladder (which is located on top of your uterus) and cause infection. Pee after sex to get rid of bacteria that may accumulate in your urethra.Don't Forget Day 1 of the Pill If you're on a 28-day birth control pill cycle and you forget the first pill of a new cycle, you're at risk for pregnancy. Why? You've been off the pill taking placebos for the past seven days. It's unlikely, but there's a shot!Keep an Eye on Your IUD In rare cases, an IUD could slip out while you're going to the bathroom, without you even knowing, leaving you at risk for pregnancy. So keep an eye out for anything amiss.