I had sex with two different men last month.  Is it possible I could be pregnant from both of them? Mari, 23

Mari, if you are pregnant it is most likely that only one of the men is the biological father.  If by chance two of your eggs matured AND the sperm from both of men was present at that moment then YES it is possible that you are pregnant with both of their babies.

If just one egg matured last month (which is what usually happens) and the sperm from both of the men was present then according to sperm competition theory, it’s most likely that the man who is not your regular partner (e.g. A hook-up or casual lover) is the father.  His ejaculate would have contained larger numbers of kamikaze/fighter sperm as well as more potent egg penetrator sperm.  In contrast your partner’s ejaculate would have contained many blocker sperm as well as less potent egg penetrator sperm.

If you were a member of an Amazonian tribe such as the Ache, Bari or Canela you would subscribe to the notion of partible paternity.   Here you would believe that it takes multiple washings of semen throughout a pregnancy to create a baby.  Thus if a woman had multiple sexual partners, ALL of them would contribute genetically in the creation of the baby--and all would be considered the baby’s biological fathers.

If a girl has foreplay and a guy’s semen gets around her vaginal area will there be a chance for her to get pregnant if she is still a virgin?   Tina, 18  

Yes Tina that can happen.  Moreover infections such as herpes and crabs can be spread with skin-to-skin contact that does not include sexual intercourse.  As for pregnancy if a girl has become a bit wet, sperm that is deposited anywhere near her vaginal opening can certainly find it’s way through her intact hymen on into her uterus, up along her fallopian tubes and into a freshly ripened egg.  

If there are cultural reasons that you must remain a virgin before marrying, then pretty much no one will be be interested in considering that you are a pregnant technical virgin.  If such an unplanned pregnancy does occur, taking the abortion pill, RU-486 does enable a girl to slough off her pregnancy without disturbing her hymen.  To avoid pregnancy altogether, keep more of your clothes on or if you must get naked don’t let your boyfriend ejaculate anywhere near your vagina.

I am thinking about becoming a single mother.  I have a boyfriend and while I’m not actively trying to become pregnant, I’m not avoiding it either.  What rights will he have should I choose not to stay with him if I do become pregnant?  Olivia, 20

Olivia, if you and your boyfriend are not actively using birth control (e.g. pills, patch, nuvaring, condoms), then it must be presumed that both of you are open to creating a and parenting a child. By engaging in unprotected sex with you, the law treats him as a potentially willing and responsible parent.  If you do not want him to be the legal father of your child, you should not be having unprotected sex with him.  

If you are truly interested in becoming a single mother by choice and you would like your boyfriend to be your sperm donor, then prior to getting pregnant you should draw up legal forms that give you full parental rights.  And to ensure that he has no rights over the future child, it’s best you engineer your pregnancy through artificial insemination.  Moreover, if you really want to ensure that you are the sole parent, then it would be advisable to go to a sperm bank rather than to use a donor who has been your lover.

If you were to become pregnant through having sex with your boyfriend he would potentially have full paternal rights over the child.  If you were no longer together, he could sue you for custody of the child.  If you retain custody, he would have the right to visit the child, to participate in making legal decisions for the child and could be expected to pay you child support.  Finally,  if he gained custody of the child, you could be expected to pay him child support!

Certainly in other times and places the creation of families has not be so legalistic, thus making your interest in being a single mother really quite “natural.” Moreover, for all non-human primates,  the mother-infant bond is considered the central bond for learning and survival.  Before the popularization of DNA tests no one knew for certain who a single woman’s baby’s father was.  The African Dogon people (who do not use any form of birth control), address this potential uncertainty by requiring all  women to stay in the tribal menstrual hut during their periods.  If a woman does not return to the hut the following month, everyone would have taken note of which man’s bed she slept in once her period ended and he would be named as the father of her child.  

How can I find out if I am still ovulating?  Maria, 49

Maria, ovulation is a crucial part of female reproduction.  When a woman ovulates it means that an egg is being released from her ovaries that can be fertilized, causing her to become pregnant. Chimpanzees, bonobos and baboons are some of the many primates that advertise female fertility through a donning a brightly colored genital swelling.  Being that these animals walk on all-fours, their swellings are right at eye-level for all troop members to see.

Humans don’t openly advertise ovulation and thus it can be a bit of a mystery.  Research has revealed that women who are near ovulation are more interested in sex and more likely to show more skin in public.  Ovulation test-kits which are available for over-the-counter purchase at pharmacies, sample a woman’s urine to predict when she will ovulate.  These can be especially useful for women who are trying to become pregnant.  Ovulation can also be signaled by noting a change in the consistency of a woman’s vaginal fluid.  At ovulation it will be stringy and stretchy, while at other times of the month it’s likely to be drier and less abundant.

Considering your age, it’s possible you have stopped ovulating.  When a woman stops ovulating, her menstrual periods stop and her menopause begins.  Full menopause is marked when a woman has not had a menstrual period for one year.  In that sometimes a woman will have a menstrual period without ovulating, you can have your doctor run a blood test to measure your hormone levels to find out if  you are in fact still ovulating.

How long into pregnancy can you continue to have intercourse?  Amy, 24

Amy each culture has its own beliefs and practices regarding sex and pregnancy.  The Bari peoples of the Amazon believe that the fetus grows as a result of repeated washings of semen throughout the pregnancy.  A Bari father-to-be works hard to grow his baby by having frequent sex with the baby’s mother.  Sometimes his efforts are supplemented by other men in his community. According to the Bari these inseminations pass on inheritable qualities, causing all men who have sex with a pregnant woman to become fathers to the growing baby.  This belief is called partible paternity and while not accurate by our understandings of cell biology, nonetheless has been seen as responsible for healthier newborns in that visiting daddies typically bring the expectant mother gifts of food.

For women who are no danger of miscarriage, having intercourse throughout the childbearing year is considered perfectly okay.  Beginning in the second trimester a pregnant woman may experience a notable glow, causing her to appear extra-beautiful and very interested in sex.  Her orgasms may be especially intense due to the increased size of her uterus.  During the final trimester couples might find the need to experiment with different positions due to the mother’s increased size.  Finally if a baby is due and not coming as expected, having sex can be just the trick to start the contractions that bring on labor.