During pregnancy preparation, conception is only possible after intercourse if you know exactly when you are ovulating. At present, clinically, the following methods are commonly used to monitor ovulation 1. Calculating menstrual cycle. For women with regular menstrual cycles, generally speaking, the day of ovulation is about 14 days before the next menstrual period, and there is a chance of conception when having intercourse 3 days before and after the day of ovulation. For women with irregular menstrual cycles, this method cannot be used to calculate ovulation. 2. Ovulation test paper monitoring. By using ovulation test paper to continuously test the morning urine, when a strong positive appears, it is the ovulation period. 3.Basal body temperature monitoring. Basal body temperature refers to the body temperature in the morning after waking up without any activity. After ovulation, there is an increase in progesterone, which can raise the body temperature by 0.3-0.5℃, and this is often used clinically as one of the signs to determine the date of ovulation. Women who are preparing for pregnancy can measure their basal body temperature daily and draw a temperature graph to observe the ovulation period. 4.B ultrasound follicle monitoring. Ultrasound is the most visual way to observe the size of the follicles. When the follicle is above 18mm, it means that the follicle is mature and may ovulate at any time. Therefore, ovulation can be monitored by these methods and the chances of conception are high only if you have intercourse during ovulation.