Although the birth control pill is nearly 100 percent effective when used correctly, incorrect use leaves some women with unwanted pregnancies.

Jana Whelan, a pharmacy technician at Kishwaukee Community Hospital said the idea of the pill is “to fool the body into thinking it is pregnant.”

Peggy Noel, a nurse practitioner at the NIU Health Center, said birth control pills are 99.9 percent effective when used correctly.

But according to a study released this week by the National Research Council, 3 percent of women who take the pill become pregnant during the first year of use.

Noel said one of the most common mistakes women make when using the pill is skipping a day or forgetting to take it at about the same time everyday.

Women often forget to take the pills home with them over weekends, she said.

About 58 percent of more than 600 women in a study conducted by the University of Michigan said they did not take a pill each day. Less than 17 percent surveyed took pills at the same time each day for maximum effectiveness.

Out of the study group, about 6 percent became pregnant, as compared to one or two pregnancies if the pill is taken properly.

Noel said women can remind themselves by taking the pill before doing a routine daily activity. For example, taking the pill just before brushing teeth or immediately when waking up in the morning.

Another common mistake women make while taking the pill that can lead to pregnancy is taking it with other medications, Noel said.

Women taking the pill should use a back-up form of birth control while taking some antibiotics, Whelan said. Women should tell their doctor they are taking the pill to be certain not to mix medications, she said.

Noel said women should know the pill “does not protect you from sexually transmitted diseases.” The best protection against diseases is a condom combined with contraceptive foam, she said.

“A lot of people assume they are protected when they are not,” Noel said.

There are other types of birth control other than the pill, she said. The trick is to get women to stop using “chance (birth control) and find a method that is effective,” she said.