I had my baby 6 weeks ago and haven't had my period yet. Is this normal?

Q: I had my first baby 6 weeks ago and haven't had my period yet. Is this normal?

A: It can take anywhere from about seven to 10 weeks for nonlactating women to resume menstruation and up to six months for fully breastfeeding women, says Sean S. Daneshmand, M.D., clinic director of maternal-fetal medicine at the San DiegoPerinatal Center, Sharp Mary Birch Hospital for Women. Why the difference? The babys suckling promotes the release of prolactin, a hormone that keeps you from ovulating, Daneshmand explains. But a woman must be nursing a minimum of every three hours around the clock, with at least 15 minutes per feeding, for ovulation to be prevented. If you give your baby an occasional bottle of formula or pumped breast milk, or even a pacifier, all bets are off. And don't think that you can't become pregnant just because you haven't gotten your period again. Within three to four weeks post-delivery, half of women who aren't breastfeeding can ovulate, Daneshmand points out.

If you prefer hormonal contraception and are breastfeeding, Daneshmand recommends progestin-only birth-control pills because they don't interfere with milk letdown. If you're not nursing, these pills are recommended for the immediate postpartum period; combination estrogen-progesterone pills should be taken only after six weeks because they increase the risk of blood clots, which can be a concern as your body heals.