Your Best Days for Making a Baby

You're ready to get pregnant, and you want to know when you're most likely to conceive. That means figuring out when you're ovulating. You can try to pick out your most fertile days on your own, but there are tests and kits that can give you a clearer idea of the best time for baby-making.

First, review the basics:

  • You can ovulate anywhere from 13 to 20 days before your next period.
  • To get pregnant, you should have sex a few days leading up to and on the day of ovulation.
  • Sperm can live up to 6 days in your body, but your egg can only survive 12 to 24 hours. That's why having sex before and during ovulation is best. You’ll raise your odds of the sperm and egg meeting.
  • You can use basal body temperature (BBT) charting to figure out if you’ve ovulated, but it isn’t foolproof.

Ovulation Predictor Kits (OPKs)

Ovulation predictor kits help you find the days when you’re most fertile. But many couples can conceive on their own without using them.

"I don't typically recommend this right off the bat," says Caren Schaecher, MD, an OB/GYN at Women's Health Care at St. Luke's Hospital in Chesterfield, MO.

But if you’ve been trying for a few months with no luck, it may help you to know your most fertile times, and these kits can help, she says.

They might also help if you have timing issues. For instance, if you or your partner travels a lot for work, you can plan ahead.

They can also ease stress if you’re feeling pressured about trying to get pregnant.

"The rest of the month they can feel like they're just a normal couple, and they're not hyper-focused on fertility," says William B. Schoolcraft, MD, founder and medical director of the Colorado Center for Reproductive Medicine.

Ovulation Predictor Kits: Urine

Ovulation predictor kits test your urine for levels of the hormone that triggers ovulation. It's called luteinizing hormone (LH). "The LH surge is typically 24 to 36 hours before ovulation," Schaecher says.


The instructions will tell you when to start checking your urine based on the length of your menstrual cycle. Then you'll test for 5 to 7 days. Some kits allow you to test more days.

Cost: About $17 and up

Ovulation Test Strips

These are the simplest and least expensive option. You hold the strip in your urine stream (or in a sterile cup you've filled with urine). Color coding will tell you if you're ovulating.

Cost: $13-$30

Digital Ovulation Tests include a digital readout, which can make it easier to see your results.

  • Digital Ovulation Test
    • Costs about $30-$50
    • Detects LH
  • Advanced Digital Ovulation Test
    • Costs about $38 for a 1-month supply and $54 for a 2-month supply.
    • Detects both LH and estrogen to predict your top 2 fertile days, plus another 4 days when you could become pregnant.

Fertility Monitor. This device stores the information from your monthly urine tests.

  • Detects both LH and estrogen. Some look for levels of another hormone, follicle-stimulating hormone (FSH).
  • Shows you low, high, and peak fertility days, adding another 1 to 5 days of fertility.
  • Stores information about your hormone cycles, so it tells you when to test and when your period is due.
  • Monitor costs about $160; the test sticks you need for the monitor cost about $50 for a pack of 30.

Ovulation Predictor Kits: Saliva

This product looks at the mineral content in your saliva when it dries.

It comes with a mini microscope you can use to look for a pattern in your saliva. It looks like a fern leaf. When you see it, you’ll ovulate sometime in the next few days.

  • Unlike urine kits, which you use only once, you can use a saliva test over and over.
  • A good option for women who want something simpler than a urine test
  • Cost: about $30

There are some problems with saliva testing:

  • Not all women will show the fern pattern or can see it.
  • You may not "fern" on all of your fertile days.

While saliva testing works for some women, it isn’t as good as urine kits. "Of all the options, the only OPKs that have been validated are urine ovulation predictor kits," Schoolcraft says.


How Long to Test?

"If you're under 36, it would be OK to try for up to a year," Schoolcraft says. "After 35, typically specialists recommend just trying for 6 months." After that time, if you've been doing everything right and still haven't conceived, it's a good idea to see a fertility doctor.

WebMD Feature Reviewed by Traci C. Johnson, MD on February 23, 2016



Caren Schaecher, MD, OB/GYN, Women's Health Care at St. Luke's Hospital, Chesterfield, MO.

William B. Schoolcraft, MD, founder and medical director, Colorado Center for Reproductive Medicine. "Trying to Conceive."

FDA: "Ovulation (Urine Test)."

FDA: "Ovulation (Saliva Test)."

Eichner, S. The Annals of Pharmacotherapy, February 2004.

Stanford, J. The American College of Obstetricians and Gynecologists, 2002.

© 2013 WebMD, LLC. All rights reserved.


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