Lesson 16 - Detecting Ovulation on Charts

Lesson Objectives:

  • Be able to detect ovulation on charts from clear ovulation patterns
  • Use BBT and other fertility signs to pinpoint ovulation

Major Points in this Lesson:

  • Basal body temperature (BBT) and other fertility signs play a critical role in detecting ovulation.
  • While you want to aim for an ideal chart, some charts are not as clear as others.
  • It can take time to learn how to interpret chart patterns.
  • Recording accurate and consistent data is paramount for clear patterns.

Throughout a woman’s cycle, the body naturally gives clues to show when ovulation may occur. Charting these fertility signs can help you target your prime ovulation days for better odds of conception. Charting typically involves taking your basal body temperature (your temperature at rest) using an in-ear thermometer, examining your cervical mucus, tracking when your period starts, and taking note of what days you have intercourse.

Most charting apps make the process easier by providing graphs that show changes in basal body temperature. On a fertility chart, ovulation is detected with a biphasic pattern, meaning lower temperatures followed by higher temperatures. Your BBT will remain higher throughout the luteal, or post-ovulation, phase. As your next cycle begins, it should normalize. If a BBT remains high, there is a chance that a pregnancy occurred. 

Until a clear thermal shift (temperatures that are higher than the previous several temperature points for a minimum of three days) is observed on your chart, you should consider yourself fertile. If you are trying to conceive, continue to have intercourse. Also cross check your BBT with other signs that could indicate ovulation. For example, a chart will often show a pattern of a thermal shift around the same time that cervical fluid dried up. That is why it’s important to record all of your fertility signs carefully.

While you may expect to see a clear pattern, that is not always the case. In some scenarios, extra flexibility and interpretation is needed to determine ovulation. If you are trying to conceive and you cannot determine ovulation clearly by your chart alone, it is recommended to consider yourself fertile unless you can prove otherwise. By continuing to believe you may be fertile, you can increase your chances of conception.