If your menstrual cycle is 28 days, your period ends on the 7th of each month. If your periods are very regular, you should ovulate about 14 days after each period ends. At this time, your eggs are mature and ready for fertilization.

- Measure basal body temperature: Every morning after your period ends, you measure your body temperature and record it. If your body temperature rises by 0.5 to 1 degree Celsius, you may be ovulating.

- Watch for symptoms: If you experience symptoms during ovulation, such as breast swelling, headache, nausea, etc., then these symptoms may mean that you are entering ovulation.

Overall, ovulation is very important in determining whether you can get pregnant. If you're trying to get pregnant, you should pay close attention to whether your eggs are ready for fertilization. If you fail to fertilize during ovulation, you can try to keep trying during your next menstrual cycle.