BBT In The Two Week Wait

The two week wait (tww) is the time between ovulation and when your next cycle is due to start (i.e. the next menstrual period). That waiting period can be like limbo because essentially there’s no way to tell if you’re pregnant or not.

Some women obsess about signs and changes that they see in their body during this period, as this can be the only way to determine at that point if they might be pregnant or not—and it’s usually too early to take a pregnancy test.

If you are tracking your basal body temperature (BBT), here are some of the things to look for that might indicate whether pregnancy has been achieved or not.


On the chart above, you’ll notice a temp dip at 5 days post ovulation (dpo). The dip is a result of a drop in estrogen due to the egg being released, and then the corpus luteum (a little hormone secreting structure in your ovary) takes over to produce progesterone which causes your temp to go back up.

The CL dip usually occurs in the first few DPO past ovulation (1 to 5 dpo) – and yes, many mistake this for an “implantation dip”.   But as with anything chart/temping related, it can be different for everyone…so not everybody will see this shift on their chart.


Again looking at the chart above, you will notice a much larger dip at 11 dpo. This was her implantation dip. An implantation dip is a one-day drop in your basal body temperature (BBT) that occurs during the luteal phase, about seven to 11 days after ovulation. This drop is seen on pregnancy charts more often than non-pregnancy charts. But, whether you get one or not, it’s no guarantee that you’re pregnant.

Usually, a dropping temperature is a sign that your period is coming or has even already arrived. Your period should not come just seven to 10 days after ovulation, so you wouldn’t expect a temperature drop at this time.

With an implantation dip, your temp will rise right back up the next day. The fall lasts just one day. (When your temperature drops because your period has started, your temp stays down and doesn’t jump back up.)

The dip may just be slightly lower than the rest of your post-ovulation temperatures. Or, it may drop below the coverline on your fertility chart. The coverline is an imaginary horizontal line separating where your temperatures on average were before ovulation as opposed to where, on average, they are after ovulation.

The dip appears during the luteal phase, the time between ovulation and your expected period. Also, implantation of the embryo usually occurs between days seven and 11 of the luteal phase. This is why some people attribute this sudden one-day dip in temperature to implantation., a free fertility charting online software company, did an informal analysis of the BBT charts on their site to see if an implantation dip might indicate pregnancy. Their analysis doesn’t qualify as a scientific study, but the results are still interesting to consider.

They did a statistical analysis of just over 100,000 BBT charts, of both pregnant and non-pregnant women. They looked for

  • Charts that detected ovulation
  • A dip in temperature of at least 0.3 F occurring after ovulation
  • The drop showing up between days five and 12 of the luteal phase

On non-pregnancy charts that detected ovulation, 11 percent had an implantation dip. On the other hand, 23 percent of pregnancy-positive charts had an implantation dip. Looking at their statistics, twice as many of the pregnancy charts showed an implantation dip.

If your chart doesn’t have a dip, you can’t draw a conclusion. Approximately 75 percent of pregnancy BBT charts did not have the dip. Most women who were pregnant didn’t get a dip.

If you have the dip, does it mean you’re pregnant? No. The dip appeared on non-pregnancy charts.

When Can I Test?

It takes at least 2-3 days after implantation for there to be enough HCG in your system to be detected by the most sensitive test available, First Response Early Result. If you do test and it’s negative, don’t fret, just wait a couple more days and test again with the First Response Early Result. 

While many pregnancy tests say that you can take them before you missed your period, this is typically only a day or two before. And if you get a negative pregnancy test using one of these early tests before you miss your period, it is more difficult to confirm that you are not pregnant.

This might be an example of a false negative pregnancy test. This is one of the reasons why it may be best to wait until you have missed your period to take a pregnancy test. The best time to test is the morning after your period was due to start.

Related Posts

Make sure you grab a copy of my FREE guide Trying To Conceive Language & my FREE Self-Care Mini Course. You can access either one by clicking on the title. These are packed full of information that you can begin implementing today to put yourself one step closer to getting pregnant, naturally.

If you’re looking for a group of like-minded women with which to share your fertility wellness journey, be sure to check out my Whole Body Fertility & Wellness Facebook group today!

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