You've yet to hear a single tick-tock, but lurking beneath your killer abs is a biological clock that will start buzzing eventually — and you can only hit the snooze button so many times.
So what do you do if you're not ready to push out a baby right this second but think you'll want to become a mom someday?
Luckily, fertility isn't a total crapshoot. And though you can't put off pregnancy indefinitely (despite exceptions like Marcia Cross, your odds of conceiving drop substantially after age 35), there's plenty you can do to help keep your body in peak baby-making form.
Watch your diet
What's good for your arteries is also good for your eggs. Jorge Chavarro, M.D., a research fellow at the Harvard School of Public Health and co-author of "The Fertility Diet," tracked the fat intake of nearly 18,000 women as they tried to get pregnant. Women who gobbled more healthy unsaturated fats (think olive oil and avocados) were less likely to experience infertility due to ovulation problems than those whose diets contained more trans fats.
Don't worry, be happy
Stress interferes with the brain's bulletins that tell your ovaries to do their monthly job of rolling out an egg, says Sarah L. Berga, M.D., chair of the ob-gyn department at Emory University in Atlanta. If you're a type A (for anxiety and angst), figure out a calm-down solution that works for you, whether it's practicing tai chi or thrashing around to the Foo Fighters, before you get ready to pee on the stick.
Get tested regularly
You were probably worried about getting pregnant that night the condom broke, but if he slipped you an infection that went untreated, you might have the opposite worry later on. "STDs can cause scarring in your reproductive organs, blocking your fallopian tubes," says Sherman Silber, M.D., medical director of the Infertility Center of St. Louis and the author of "How to Get Pregnant." The tubes can also end up filled with fluid (a residual effect of the infection) that can prevent implantation of an embryo.
Clear the air
Sucking on Marlboro Lights can make your eggs go up in smoke. "Smoking constricts blood vessels, including those that feed the ovaries, which accelerates the loss of eggs," Silber says. You say you know lots of Puff Mommies who got knocked up, no prob? "Sure, women who smoke can get pregnant — when they're young," Berga says. "But smoking can cause you to become infertile earlier than you would as a nonsmoker."
Pick a winner
If you're in a monogamous relationship, go — or stay — on the Pill. OCs can cut your risk of fertility-damaging conditions like pelvic inflammatory disease, endometriosis and endometrial cancer; and because women on the Pill aren't ovulating, their risk of ovarian cysts and ovarian cancer is also reduced. More good news: "Many women get pregnant the next cycle after quitting," Silber says.
Check out your bod
Yeah, you see your gyno every year, but what about the rest of your anatomy? A major cause of infertility is undiagnosed or untreated medical problems, including diabetes, thyroid disease, or polycystic ovarian syndrome (PCOS), which interferes with your body's hormonal balance. Get a physical every other year (and check out womenshealthmag.com/screenings for the tests you should ask for).
Skip the scalpel
No one wants to spend her period week in the fetal position suffering from endometriosis or ovarian cysts. But if your doc wants to surgically remove growths, do all you can to avoid going under the knife. "Your body puts all its eggs in the ovary's superthin outer layer [the cortex] — so nicking it with a scalpel or a laser has obvious consequences," Silber says. Ask whether you can try a noninvasive option first, like the Pill. If you must have surgery, tell your doctor not to cauterize or remove any part of the cortex.
Count your eggs before they hatch
During your next Pap, Silber says, ask about getting a vaginal ultrasound to determine your antral follicle count — an estimate of how many eggs you have left. Female fertility is a numbers game: You're born with all the eggs you'll ever have, and in addition to the one or two that are released during ovulation, others are dying off as you age. Some women have enough good eggs to last well into their forties; others run out sooner. If your count is low, you might consider putting your ova on ice (see next item).
Freeze your assets
If sperm are the tough Gap T-shirts of the reproductive world, your ova are like gauzy couture dresses. Until recently, this meant that freezing your eggs was mostly out of the question (the ice crystals that form during the slow-freezing process used on embryos damages eggs). But a new method, called vitrification, involves very rapid icing that safely solidifies the eggs. It's pricey — $6K and up for a single procedure (and the number of good eggs you'll get varies), plus annual storage fees — and it tends to be most successful when you and your ova are young (in your 20s). Though there are no long-term data on the procedure, it's worth investigating if you know your antral count is low or if you're about to undergo a fertility-zapping procedure like chemotherapy. (Check out infertile.com to find out more.)