Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Health & Pregnancy

Font Size

How to Chart Your Menstrual Cycle

Getting pregnant is all about timing. You want to make sure the conditions are right for egg and sperm to meet. Your menstrual cycle can give you clues about when your body is ready to start the process.

The first step is to learn the days when you’re most fertile. A woman with a 28-day menstrual cycle, for example, has about 6 days each month when she can conceive – the day one of her ovaries releases an egg, called ovulation, and the 5 days before. Timing sex within that window is key.

To figure it out, start charting your menstrual cycle and recording how long it lasts. Day 1 is the first day of your period. Since the length of your cycle can vary slightly from month to month, it’s best to keep track for a few months.

Then, subtract 18 days from the length of your shortest cycle: this is the first day you’re likely to be fertile. Next, subtract 11 days from the length of your longest cycle: this is the last day you’re likely to be fertile. Having sex between those two dates will give you the best shot at getting pregnant.

It’s also a good idea to pay attention to the signs that your body is ready to ovulate.

Basal Body Temperature

Your basal body temperature (BBT) is your temperature first thing in the morning. Just after you ovulate, it rises slightly -- sometimes by less than a degree -- and stays higher until your period starts. If you record your temperature every day, you can detect the subtle changes that mean one of your ovaries has released an egg.

How to take your BBT:

  • Use a basal body thermometer. They’re more sensitive than standard ones and will show temperature changes down to a fraction of a degree. You can get them at many pharmacies for less than $20.
  • Take your temperature at the same time each morning, always before you get out of bed. (Try keeping the thermometer on your nightstand.) Even getting up to go to the bathroom can affect your body temperature, as can smoking, drinking, or getting a bad night’s sleep.
  • Remember, your BBT won’t tell you exactly when you’ve ovulated, and it may take a couple of months before you start to see a pattern. You’re most likely to get pregnant 2 or 3 days before your ovary releases an egg, and then another 12 to 24 hours after that. When your temperature has spiked for 3 days, your chances of conceiving drop.

Pregnancy Week-By-Week Newsletter

Delivered right to your inbox, get pictures and facts on
what to expect each week of your pregnancy.

Today on WebMD

hand circling date on calendar
Track your most fertile days.
woman looking at ultrasound
Week-by-week pregnancy guide.
Pretty pregnant woman timing contaction pains
The signs to watch out for.
pregnant woman in hospital
Are there ways to do it naturally?
slideshow fetal development
pregnancy first trimester warning signs
What Causes Bipolar
Woman trying on dress in store
pregnant woman
Close up on eyes of baby breastfeeding
healthtool pregnancy calendar
eddleman prepare your body pregnancy