Question - When is a woman least likely to become pregnant during her menstrual cycle, and can she become pregnant during her menstrual period?

Question: When is a woman least likely to become pregnant during her menstrual cycle, and can she become pregnant during her menstrual period?

Answer: Condoms should always be used during vaginal and anal intercourse to help prevent the spread of sexually transmitted diseases like AIDs and Chlamydia. For dating couples, the use of a condom is not optional. While AIDs and STDs may not be mentioned on the nightly news, they are spreading through the sexually active population, including teens.

The term "sexually active" applies to anyone who is considering or who has engaged in sex with a partner one or more times. If you are "considering" having sex with a partner, you should consider yourself sexually active, because the difference between being and not being sexually active is about one second. Safe sex in not an option.

The above questions are not easy to answer, as women have menstrual cycles that vary in length. They varying from 21 to 35 days, with 28 days being the average. It is not unusual for women, and especially teens, to have irregular menstrual cycles and to skip menstrual periods, to further confuse things. This allows for a large margin of error when one starts making assumptions.

The Rhythm or Calendar method of birth control, basing a woman's fertility on her menstrual calendar, is about 80% effective in preventing pregnancy. This means 20 out of every 100 women who use this method for one full year will become pregnant. Using the Pill, 8 women will become pregnant during the same time period. That number increases to 15 when a condom alone is used and 27 when the withdrawal method is used. While no method of birth control is 100% effective in preventing pregnancy, the rhythm or calendar method is one of the least effective.

"Were no contraceptive used, it is estimated that 60 to 80 sexually active women in every 100 would become pregnant in the course of a year. Confirmation of a sort is provided by teenagers, who now account for over one million pregnancies yearly." Source: How Big is Big by Dr. Zev Wanderer & Dr. David Radell.

For more detailed information on the rhythm method please see the website linked to below. The failure rates of the above mentioned birth control methods was obtained from that website.

http://www.plannedparenthood.org/

Sperm can live inside the female reproductive organs for up to seven days, based on current data; it was once thought to be less. An egg cell, ovum, can be fertilized for up to 48 hours following ovulation. This means an average woman can become pregnant if sperm comes in contact with her vulva or vagina during nine days, each menstrual cycle. The challenge lies in determining those nine days. As the rate of effectiveness of this birth control method indicates, that is not an easy task.

Assuming an average cycle of 28 days, ovulation usually occurs on the 14th day. Day 1 is the first day of menstruation, bleeding. Day 1 through 6 are "safer" days to have unprotected sex; there are no truly "safe" days to have unprotected sex. If a woman has unprotected sex during days 7 through 16 there is a greater chance of conception. To be on the safer side, to allow for variability in when ovulation actually occurs, days 7 through 19 should considered a woman's fertile time. Since ovulation may occur at any point during a twenty-four hour period, a woman's egg cell may be viable for all or part of three calendar days. Vaginal intercourse or unprotected sex during days 1 through 6 and 20 through 28 is "less" likely to result in pregnancy. Women with menstrual cycles shorter than 27 days are at an increased risk of having this method fail, as they ovulate closer to their menstrual period.

28 Day Menstrual Calendar
Day 1 First Day of Menstruation	Day 2	Day 3	Day 4	Day 5 Last Day of Menstruation	Day 6	Day 7 Sperm Life Span Day 1
Safer	Safer	Safer	Safer	Safer	Safer	Unsafe

Day 8 Sperm Life Span Day 2	Day 9 Sperm Life Span Day 3	Day 10 Sperm Life Span Day 4	Day 11 Sperm Life Span Day 5	Day 12 Sperm Life Span Day 6	Day 13 Sperm Life Span Day 7	Day 14 Ovulation
Unsafe	Unsafe	Unsafe	Unsafe	Unsafe	Unsafe	Unsafe

Day 15 Viable Egg Cell Day 1	Day 16 Viable Egg Cell Day 2	Day 17 Added Safety	Day 18 Added Safety	Day 19 Added Safety	Day 20	Day 21
Unsafe	Unsafe	Unsafe	Unsafe	Unsafe	Safer	Safer

Day 22	Day 23	Day 24	Day 25	Day 26	Day 27	Day 28
Safer	Safer	Safer	Safer	Safer	Safer	Safer

Given all the variables, it is possible for a woman to become pregnant if she has unprotected intercourse during her menstrual period. Is it likely to occur, no. If you are having your period and you ovulated two weeks prior, the egg cell has long since disintegrated. But if you have a short or irregular menstrual cycle, and given that sperm can live inside your body for up to seven days, it is possible for sperm to still be alive when you ovulate. As the above calendar illustrates, there is only one day between when menstruation ends and the unsafe period begins, not a lot of room for error even with a 28 day cycle. Certainly having unprotected intercourse during a woman's menstrual cycle is lower in risk than if you did so mid-cycle, unless of course you have short menstrual cycles. Because of the presence of menstrual blood, sex during a woman's menstrual cycle is considered higher risk when it comes to STD's like AIDs. You can read more about this on the page about Menstruation and Sex.

You can certainly engage in sexual activities during a woman's "unsafe" time as long as those activities do not include intercourse, or any activity where there is a chance sperm can come in contact with a woman's vulva, vagina, or inner thighs. You can engage in other sexual activities like masturbation, mutual masturbation, erotic massage, genital massage, and oral sex. During the unsafe time, genital to genital contact should be avoided.

It should be noted that vaginal penetration is not required for conception to occur, and virgins and twelve-year-olds become pregnant. There are teens and women who become pregnant the very first time they engage in vaginal intercourse, even if the penis was not fully inserted or was withdrawn prior to ejaculation. If a woman or teen has experienced her first menstrual period, she can become pregnant, and becoming pregnant is not nearly as difficult as you may have been led to believe; it is not a miracle, but rather a common occurrence. There are 6,000,000,000 people in the world to prove this point.

Condoms should be used any time a penis comes in contact with a woman's vulva, vagina, or anus, as I mentioned above penetration is not required for pregnancy to occur, nor does a man need to ejaculate for sperm to be present. Precum, the clear fluids that seeps from the penis during sexual arousal, can contain sperm. While pregnancy is unlikely to result from anal intercourse, if sperm travels from the area around the anus to the vulva and vagina it is possible, but anal sex is also a higher risk sexual activity in regards to STDs.