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When it comes to birth control, many people want to just set it and forget it. It’s there, it does its job, who wants to think about it, right?

But bungling birth control is all too common. In fact, half of all pregnancies in the United States are unintended. Yikes.

To make sure you can count on your contraceptive, here are the potential pitfalls.

You're not using it

It’s no secret that birth control is a touchy subject, particularly in the US. Political and religious leaders fight about it endlessly, and it’s all tangled up in personal choices about—shhhh!—sex.

But the bottom line is if you’re sexually active, and now isn’t a great time to start a family, you should select a type of birth control that works for you. Luckily, there are a ton of birth control options out there.

You’re taking rifampin

The antibiotic rifampin can undermine hormonal contraception, including the pill, the patch (Ortho Evra), or the vaginal ring (NuvaRing).

Some anticonvulsants, oral medications for yeast infections, HIV drugs, and the herbal supplement St. John’s wort can also be a problem for these types of birth control, as well as for contraceptive implants (Implanon), according to Planned Parenthood.

Bottom line? Check with your doctor about possible interactions and medications that can make your birth control less effective.

You use the wrong lubricant

Oils or oil-based lubricants (including Vaseline, baby oil, and mineral oil-based body lotions) can dramatically weaken latex condoms in just 60 seconds.

Choose a water- or silicone-based lubricant, available in the family-planning aisle in drugstores and supermarkets. Also keep in mind that many lipsticks contain oils that can weaken latex.

Your nails nick your sponge

Long fingernails can nick or tear contraceptive sponges during insertion, which reduces the efficacy.

Even small nicks or tears can get bigger during intercourse, so keep your nails short or be sure to use care. It’s also important not to nick or tear condoms with jewelry, fingernails, or teeth.

You’re inconsistent

Missing three or more combination birth control pills (the most commonly used type, which contain both estrogen and progestin) means all bets are off until you’ve taken the pills again for seven days straight—so you need to use backup birth control during that week.

If you miss even one or two of the first pills of a pack, it also means you need seven days of backup birth control (such as condoms).

Progestin-only pills need to be taken at the same time each day, with backup contraception needed for 48 hours if you get off-schedule by more than three hours.

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More from Health.com:

7 Common Birth Control Side Effects

12 Types of Birth Control: Which is Right for You?

Birth Control for Women Over 30

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You haven’t explored the options

Some people just can’t remember to take a pill every day. If that sounds like you, think about switching to a "more 'forgettable' method that doesn’t rely on taking a pill every day, like a contraceptive implant or an intrauterine device," says Alison Edelman, MD, a clinical gynecologist and associate professor at Oregon Health & Science University in Portland.

You could also consider birth control injections (Depo Provera), a shot in the arm that lasts 3 months, as well as sponges, rings, patches, diaphragms, and more. Check out the variety of choices at Planned Parenthood.

You're on the wrong pill

People call it "the pill," but there are a bunch of different types, with some more effective than others. If you’re breast-feeding or have heart disease, migraines, or other reasons you can’t take estrogen, it may make sense to be on a progestin-only pill (or “mini-pill”), but a combination pill provides more pregnancy protection.

“Choosing between birth control pills is more of an art than a science,” says Dr. Edelman. Talk to your doctor about balancing the highest level of efficacy with your other needs and concerns.

You pick the wrong condoms

Condoms that are too small can break, and there is some evidence that polyurethane condoms may break more frequently than latex ones.

Latex, polyurethane, and lambskin condoms all protect against pregnancy, but lambskin condoms may not protect against HIV. So unless a latex allergy is an issue, lambskin condoms may not be your best option.

You skip backup

If you get a contraceptive implant (Implanon) or start taking a combination pill within five days after your period starts, you don’t need backup birth control, but if you start any other time during your cycle, you need condoms or another birth control method for the first seven days.

For progestin-only pills, you need backup for the first 48 hours of use. Whatever type you choose, check with your doctor to find out if you need backup until it starts working.

Click here for more birth control mistakes at Health.com.