Ovulation refers to the time when a woman's eggs are released from the ovaries into the fallopian tubes, and usually lasts about three days. During this period, women are most fertile and most likely to become pregnant. However, for some women, they may miss ovulation and be unable to get pregnant. Therefore, it is very important to understand the cycle and pattern of ovulation.

So, how to determine ovulation? Generally speaking, it can be determined by the following methods:

1. Measure basal body temperature: When women wake up every morning, measure their body temperature and record it in a table. Before ovulation, the body temperature will rise by 0.3-0.5 degrees, while after ovulation, the body temperature will drop by 0.3-0.5 degrees. By measuring basal body temperature, the cycle and pattern of ovulation can be determined.

2. Observe the menstrual cycle: If the menstrual cycle is irregular, you can determine the ovulation period by observing the menstrual cycle. Generally speaking, a normal menstrual cycle is 28 days, but if the cycle exceeds 30 days, further examination is needed.

3. Use a calendar: Women can use a calendar to determine when they are ovulating. In the table, you can record a woman's menstrual cycle and date, and calculate the ovulation period in each cycle.

4. Observe symptoms: Some women may experience symptoms during ovulation, such as nausea, vomiting, headache, breast swelling, etc. If a woman experiences these symptoms, she may be ovulating.

To sum up, it is very important to understand the cycle and pattern of ovulation. If a woman misses ovulation, she can use the above methods to determine and take steps to avoid pregnancy. At the same time, women should also maintain good living habits, such as regular work and rest times, healthy diet and appropriate exercise, to improve fertility.