You shouldn’t take antibiotics because they mess with your birth control
According to Anate Brauer, MD, attending physician, Greenwich Hospital and NYU Medical Center, there is really only one antibiotic, rifampin, that has been shown to decrease the efficacy of hormonal contraception such as estrogen delivered through a ring or patch. “While there are many reports of failed contraception while taking antibiotics, rifampin is really the only one antibiotic that has been shown to increase activity of these liver enzymes, thereby making this method of contraception less effective,” she says. “If you are prescribed rifampin, or any other medication that increases metabolism of hormonal contraception (anti-fungals, anti-seizure medications, and even some herbal supplements such as St. John’s wort), use a form of barrier protection such as condoms.”
You can’t get pregnant while on the birth control pill
When taken properly, oral contraceptives are very effective—but not 100 percent effective, explains Dr. Brauer. “Oral contraceptive pills contain estrogen, which keeps your body from growing an egg and ovulating,” she says. “If you are on ‘inactive’ pills for too long or miss pills, it is possible to have an ‘escape ovulation,’ meaning your body has had a long enough break from the active pills to grow an egg and ovulate it.” Escape ovulations are less common if you take active pills continuously or if the inactive pill window is shorter—four days versus seven with some pills. If you are late starting your active pills, or have missed pills, she recommends using a secondary form of contraception such as condoms. (Here’s what you need to know before going off birth control.)
You can’t get pregnant during your period
It might not be easy to get pregnant while you’re on your period, but it’s possible. “Some women with shorter intervals between periods (for example 21 days between each period) experience ovulation (the 24-hour window when the egg is available for the sperm to fertilize) on day seven or eight, so they are prone to getting pregnant at the end of a long period,” explains Sherry Ross, MD, OB/GYN, and women’s health expert and author of She-ology. “With fewer days between each period, you will ovulate earlier in the month.” Women who have a period every 21 days that last longer than seven days, however, can get pregnant on days five through seven if they have unprotected sex. “Even though the risk is small, pregnancy can happen since sperm can live for three days!” (Because pregnancy on the pill is rare, here are some other medical reasons for a missed period.)
If you douche after sex you won’t get pregnant
Despite what you may have read or heard, women’s health experts recommend against using douches for cleaning the vagina and especially for preventing pregnancy. “This internal vaginal cleaning is not a recommended routine,” explains Dr. Ross. She points out that the active ingredients used in most douches can upset the healthy vaginal environment and pH balance and create a yeast or bacterial infection. “There is never a reason to douche your vagina!” Dr. Ross says.
The withdrawal method is a reliable birth control method
“Pulling out” definitely does not work, says Dr. Ross. “Right before ejaculation, your partner might have released some fluid called ‘pre-ejaculation,’ which may have active and viable sperm that can make you pregnant.” In other words, use birth control if you are not trying to become pregnant.
You can’t get pregnant if you are breastfeeding
If you haven’t had a period after giving birth, an unplanned pregnancy is more likely since you ovulate before getting a period, Dr. Ross explains. “During the postpartum recovery, you think you can’t get pregnant until a period returns at regular intervals,” she says. “Unfortunately, this is not the case—ask anyone who has had children less than 12 months apart!” Also, you may want to check out these surprising facts about fertility you might not know—but should.
You can smoke while on birth control
Smoking is always a bad idea, and it’s worse if you’re on the pill. It’s especially harmful if you’re over 35 and on the pill, explains Dr. Ross. “The hormones in the pill, namely estrogen and progestin, can make your blood thicker than usual and cause hypercoagulation, which is the medical term for causing excessive clotting that can cause blood clots,” she says. “Women who are high risk for blood clots include those using estrogen-containing birth control who smoke cigarettes over the age of 35.” Bottom line: Quit smoking, especially if you’re on the pill.
If you have a history of blood clots, you can still take the birth control pill
Even non-smokers should avoid the pill if they have a history of blood clotting, says Dr. Ross. “Blood clots can develop in the veins in your legs and block the blood flow in different parts of your body depending on where the clot travels,” explains Dr. Ross. If you have a history of blood clots, it’s not recommended that you take birth control for the reason that it could increase your risk of having blood clots in the future. (Make sure you know these silent blood clot symptoms.)
You don’t need a condom if your partner says they don’t have any sexually transmitted infections
Never take anyone’s word that they tested clean. “Even if your partner goes to his or her doctor to get an STI check-up and gets a clean bill of health, there is still a chance to contract STIs through sexual activity,” says Dr. Ross. “HPV and HSV are two viruses that are difficult to find during a routine checkup on a man’s penis or woman’s vagina unless there is an active wart or lesion.” Your best mode of protection is to use condoms no matter what.
Medically reviewed by Tia Jackson-Bey, MD.
Next, learn which questions you should ask your gynecologist on your next visit.