Ovulation refers to the time period when eggs are released from a woman’s body, and is also an important period for women to conceive a fetus. If you want to know when to start trying to get pregnant, or if you want to understand your fertility, it's important to know how to know when you're ovulating.

To know when to start preparing for pregnancy, you can start from the following aspects:

1. Observe symptoms: During the ovulation period, women may experience symptoms such as a slight increase in body temperature and increased vaginal secretions. These changes can help you determine when to enter the ovulation period.

2. Use a pregnancy test stick: A pregnancy test stick is a simple and effective method that can help you detect whether you are pregnant. Generally speaking, pregnancy test sticks need to be used between the 10th and 14th days of a woman's menstrual cycle.

3. Observe your menstrual cycle: Observing your menstrual cycle can help you determine when you are ovulating. If you find that your menstrual cycle becomes regular, you can easily predict when you will be ovulating.

4. Consult your doctor: If you suspect you are pregnant or want to know more about your fertility, you can consult your doctor. Your doctor can help you determine when to start preparing for pregnancy and provide necessary health advice.

To sum up, knowing how to know when you are ovulating can help you better prepare for pregnancy and improve your fertility. If you're hoping to get pregnant, be patient and look for the best times in a woman's menstrual cycle to get pregnant.