9 Things Your Doctor Wants You To Know About Birth Control

Lederman says skipping a dose is the most common mistake women make when taking OCPs. "Forgetting to take a pill is a common cause of contraceptive failure." Yikes. To remember to take your pill, try setting an alarm on your phone or using an OCP reminder app.

Everyone misses a pill once and a while, and you can try to make up for it. "In these instances, an active pill should be taken as soon as possible," Lederman says. "In cases where two pills are missed, a backup form of contraception should be used for seven days." Got it?

"In the early days of OCPs, the doses of both the estrogen and the progestin were quite high," Ledermen says. "As a result, there was a slight increased risk for cardiovascular issues such as high blood pressure, heart attacks, strokes and blood clots." He notes, however, that "lower doses of estrogen and progestin in currently available OCPs have dramatically decreased these risks," making them a safe option for women.

According to Klein, "women with a predisposition for blood clots—meaning they've had a blood clot in the past or someone in their family has (which would make that woman a carrier of that gene)" should avoid taking OCPs. Additionally, he says, "the pill is contraindicated for smokers over the age of 35." As if you needed another reason to quit your cigarette habit.

Lederman emphasizes how important timing is to effective use of birth control. "An estrogen/progestin containing OCP can be taken at any time during the day," he says. "However, unlike estrogen/progestin containing OCPs, a progestin-only pill needs to be taken at the same time each day (within three hours) to maximize contraceptive efficacy."

Klein adds, "there's a lot of cushion with the combined hormone pills. Those are more forgiving than the progestin-only pills." Choose OCPs wisely.

If you've ever seen a pharmaceutical ad on TV, you know that drugs come with side effects. "Common early side effects of OCPs include bloating, nausea, mood changes, breast tenderness, and headaches," Lederman says. If you don't feel like your symptoms are getting better over time, or are disruptive to your life, you should discuss switching pills with your doctor. And, always ask your doctor what to expect with each OCP.

Lederman says that often, side effects from taking OCPs subside after a few months. A watch, and wait-and-see approach is best to dealing with side effects from your OCPs, and, of course, an open dialogue with your doctor.

Klein says taking oral contraceptive pills has "no effect on a woman's fertility," underscoring that there's no evidence to link oral contraceptive pills with increased or decreased fertility. "A woman is losing about 40 eggs per cycle on or off the pill," Klein says, which is good news for women who are taking OCPs and want to have children in the future.

Klein tells me there is no evidence of weight gain with OCPs these days. As for acne, "some pills a certain type of progesterone are actually FDA approved to treat acne." So, if acne is an issue for you, ask your doctor which kind of OCPs can keep you child and acne free.