Does a Triphasic Pattern Mean You’re Pregnant? 7 Things You Need to Know

Many women use BBT (basal body temperature) charts to help them predict ovulation. Some do it because they’re having difficulty getting pregnant. Others do it because they want to conceive as quickly as possible.

If you’ve been keeping track of your BBT, you may have heard some women talking about “triphasic” charts. What exactly is a triphasic chart? How does it differ from a BBT chart?

First, a little background:

Charting Your BBT

If you’re trying to get pregnant, charting your BBT is a smart idea. What you do is measure your basal body temperature throughout the month to predict ovulation.

Ovulation, as you know, is the time you can get pregnant.

BBT charts typically show two temperature levels:

  • Lower temps (pre-ovulatory)
  • Higher temps (post-ovulatory)

This type of chart is known as “biphasic.” After the body switches to a higher temp post-ovulation, it generally hangs in the same range until your next cycle starts.

The higher-temp switch typically happens shortly after ovulation (usually in the middle of your cycle).

7 Things to Know About Triphasic Charts

Now that you understand what a biphasic chart (the most common type of BBT chart) is, let’s take a closer look at what a triphasic chart actually is.

1. Triphasic Indicates a Second Temperature Shift

A chart with a triphasic pattern has two distinct temperature shifts: one after ovulation, and one in the middle of the luteal phase. For the average women, the middle of the luteal phase occurs about 7-10 days after ovulation.

In order for this to be a confirmed temperature shift, the higher temperature needs to be sustained for at least three days.

2. The Luteal Phase Occurs after Ovulation 

The luteal phase is, essentially, the second half of your cycle—the phase in between ovulation and your next period. During this phase, progesterone is released to ripen the uterine lining. This creates a soft “bed” for a fertilized egg to implant itself. The ripening of the uterus happens every cycle after you release an egg, regardless of whether it’s fertilized or not.

3. A Triphasic Chart Can Indicate Pregnancy

Many women believe that a triphasic chart can be an indication of pregnancy, because progesterone levels usually spike about a week after conception. The higher levels of progesterone thicken the lining of the uterus, preventing other eggs from being released. This activity naturally raises the body’s temperature.

If you’re seeing a triphasic BBT pattern on your chart, don’t get too excited yet. While it can be an indication of pregnancy, it’s not a guarantee.

4. Non-Pregnant Women Can Also See Triphasic Patterns

Some women who aren’t pregnant will also see two temperature shifts during their cycle, and this can be completely normal. In some cases, progesterone levels reach their peak right in the middle of the luteal phase before they dip back down again. This can cause a second temperature shift.

It’s also important to know that many pregnant women don’t see triphasic patterns on their charts, so this isn’t a true confirmation of pregnancy – only a possible indicator. If you don’t see this pattern, that doesn’t mean you aren’t pregnant.

5. Don’t Take an Early Pregnancy Test If Your Chart is Triphasic

You’re eager to find out if you’re pregnant—that’s understandable. But even if it looks like your chart may be triphasic, it may not be a good idea to run out and get an early pregnancy test.

Many women see this second temperature shift, get excited, and take a pregnancy test before their period is even late. Bad idea.

Here’s the thing: pregnancy tests only look for hCG, the pregnancy hormone. They don’t look at your progesterone levels. Even if you have high progesterone levels, your pregnancy hormone levels may not be high. And if you are pregnant, it can take some time for hCG levels to build up in your system.

In other words, you may take the test too early and wind up with a BFN (Big Fat Negative) even if you are pregnant. Always wait until after your missed period to take a pregnancy test. By this time, hCG levels should be high enough to show up on the test.

6. If Your Chart is Triphasic, Look for Other Pregnancy Symptoms

Remember, just because your chart is triphasic does not mean you’re pregnant. But if you do see this pattern on your chart, be on the lookout for other early pregnancy symptoms because you may be expecting.

Common early pregnancy symptoms include:

  • Breast tenderness
  • Abdominal pain or light cramps (may be an indication of implantation)
  • Mood swings
  • Extreme fatigue
  • Weird food cravings or aversions
  • Indigestion 

7. If You’re Charting Your BBT, Make Sure You Do It Right


A BBT chart can help you predict when you’ll be ovulating, but it can also help you look for signs of a triphasic pattern. Of course, you need to know how to take your basal body temperature properly if you want this to work.

Here’s how to take your BBT:

  • Make sure that you take your BBT before rising in the morning. This means going to sleep with the thermometer by your bed. Take your temperature before you make any movements, and that includes getting up to go to the bathroom.
  • Always take your temperature at the same time every single morning—no excuses!
  • Make sure that you’ve had at least three hours of consecutive sleep before you take your temperature.
  • Always use the same thermometer when charting your cycle. A different make or type of BBT thermometer may give a slightly different reading that can throw off your chart completely. Don’t make this mistake.

You can take your temperature orally (by mouth) or vaginally; it’s up to you. Just follow the points above to ensure that your results are accurate every time.

Charting your BBT can help you get pregnant faster, and a triphasic BBT chart may be an indicator that you’re pregnant. But don’t take this reading to heart—many pregnant women never saw this pattern on their charts. Wait until your missed period to take a pregnancy test to confirm whether you’ve conceived.