Any couple trying to conceive knows how nerve-wracking the two-week wait—the time between ovulation and when you can take a pregnancy test (or your period shows up)—can be.
Here's what you can expect during this stressful time, courtesy of Helen Kim, M.D., associate professor of Obstetrics/Gynecology and Director of the In Vitro Fertilization Program at the University of Chicago.
It's a cruel reality that PMS and the early signs of pregnancy are nearly identical. The reason? You produce more progesterone the week after ovulation—whether or not you're pregnant. Progesterone is the hormone responsible for many PMS symptoms, like bloating, breast tenderness, and mood swings. If you're not pregnant, you'll stop releasing the hormone about 10 days after ovulation. (As levels wear off, your symptoms subside, the uterine lining sloughs off, and you get your period.) If you are pregnant, you'll continue producing progesterone (and experiencing PMS-like symptoms). "The difference between PMS and early pregnancy is very subtle," says Dr. Kim.
Implantation bleeding, which occurs in about 30 percent of pregnancies, can be mistaken for a period. It occurs around the time you expect your period (or a few days sooner), when the fertilized egg attaches to the lining of your uterus. Like a period, it causes bleeding and mild cramping, but there are a few distinctions: "Implantation bleeding tends to be lighter and shorter in duration than a period," says Dr. Kim. "You may have spotting instead of full days of flow." It's also likely to be light brown or black, instead of red. But if you don't experience implantation bleeding, don't fret. You can still be pregnant and have a healthy pregnancy without it.
Although there's just a 15 to 25 percent chance of becoming pregnant each month (depending on your age), it's still important to act like you're pregnant until you know for sure. Avoid alcohol, limit yourself to one to two cups of coffee per day, skip fish high in mercury, and avoid raw or undercooked seafood, meat, poultry, and eggs. "Don't make yourself crazy about restrictions, but treat yourself as if you're pregnant—you could be," says Dr. Kim.
"If you normally engage in moderate-intensity physical activity, keep it up," says Dr. Kim. Exercise is a great way to relieve stress, and stress affects fertility, she says. (Check out 33 reasons to exercise now for benefits of working out during pregnancy.)
Still, Dr. Kim warns that this isn't the best time to adopt a new or intense training program, which can put too much stress on your nervous system. Activities that significantly raise your core body temperature, such as hot yoga or heated spinning, could affect implantation.
If you get your period less than 14 days after you ovulate, it could be a red flag that something is affecting your ability to become pregnant. It could be as minor as miscalculating ovulation. Or it could be a condition called luteal phase defect. "This means your body isn't producing adequate levels of progesterone to maintain a pregnancy," says Dr. Kim. Your doc may prescribe extra progesterone following ovulation to help lengthen your luteal phase.