How to know the day of ovulation

Girls go through ovulation every month, which is when the eggs in the body are discharged. If you have sex at this time, the chance of conception is relatively high. We can calculate the approximate time of ovulation based on the menstrual cycle. Generally, ovulation occurs about 14 days after the onset of menstruation. To correctly determine the date of ovulation, we can use a thermometer or uterine mucus test.

1. Menstrual cycle

The average menstrual cycle of women around the world is 28 days. Generally speaking, as long as it is a regular, normal menstrual cycle with ovulation, the luteal phase of menstruation after ovulation is relatively fixed, averaging 14 days. Therefore, if your menstrual cycle is normal and regular, then starting from the first day of the next menstrual period, counting down 14 days or subtracting 14 days is the ovulation day. The ovulation day and the 5 days before and 4 days after it are called the ovulation period.

For example, if your menstrual cycle is 28 days and the first day of your period this month is August 1st, then the first day of your period next month will be August 29th. Subtract 14 days, and you get August 15th, which is your ovulation day. The first 5 days and the last 4 days, that is, August 10th to 19th, are your ovulation period.

It should be noted that this calculation method is only valid for women with regular and normal menstrual cycles.

2. Basal body temperature

Basal body temperature, also known as resting body temperature, refers to the body temperature displayed by the human body's basal metabolism after 6 to 8 hours of sleep without any activity.

During the menstrual cycle, the follicular phase occurs before ovulation, during which the ovaries secrete estrogen, and the basal body temperature mostly fluctuates below 36.5°C. After ovulation, a corpus luteum forms in the ovary, which mainly secretes progesterone. Progesterone has a thermogenic effect on the central nervous system, raising the basal body temperature by 0.3 to 0.5°C. The temperature increase continues until 1 to 2 days before the onset of menstruation, when it begins to decline. In this way, in a menstrual cycle with ovulation, with ovulation as the boundary, the body temperature is low in the first half and high in the second half. This high and low is what is medically called a biphasic basal body temperature curve.

A biphasic body temperature indicates ovulation; if there is no high-low change in body temperature, it is called a monophasic body temperature, which is usually a non-ovulation body temperature. If the body temperature rises after ovulation and remains for about 12 to 14 days, it means that the corpus luteum is functioning well.

Since there are many factors that affect the change of body temperature, if you use the basal body temperature method, you must insist on measuring it every day, especially when you are close to ovulation. Draw a curve on the basal body temperature chart. Generally, you should measure it continuously for at least 3 menstrual cycles to summarize your own ovulation pattern.

However, basal body temperature is a retrospective indicator. If you plan to try to get pregnant this month and measure your basal body temperature, you may have measured a low temperature before the temperature rose, but you are not sure whether the temperature will be lower afterwards. Moreover, even if this extremely low temperature indicates ovulation, it is often more than 32 hours before you can tell. Therefore, basal body temperature is a retrospective indicator and should be combined with other examination methods.

3. Cervical mucus

Cervical mucus mainly refers to the mucus secreted by the cervical canal. Cervical mucus is most abundant on the eve of ovulation and on the day of ovulation, so you can determine whether it is the ovulation period based on the condition of the mucus.

The specific operation is to start daily observation and recording from around the 10th day of the menstrual cycle. If you find transparent mucus with a stringy appearance and the length is over 8cm, you are close to ovulation. If it is over 12cm, you should ovulate within 24 hours.

4. Urine Luteinizing Hormone

This method mainly uses urine luteinizing hormone test strips to detect ovulation through urine. Because, when the egg is about to mature, the hypothalamus receives a signal, and then tells the anterior pituitary gland to quickly secrete luteinizing hormone, forming a very steep luteinizing hormone release peak, which is the luteinizing hormone peak. This peak lasts about 48 to 50 hours from beginning to end. This peak in the blood causes ovulation. Most follicles ovulate within 24 hours, and the average ovulation time is 16.5 hours after the peak appears. The latest ovulation will be within 48 hours. The urinary LH peak is 4 to 6 hours later than the blood peak. The blood and urine LH peaks have a good correlation, and the overlap rate is very high. Therefore, most people ovulate within 20 hours after the urinary LH peak, and ovulation mainly occurs 12 to 16 hours after the peak. A small number of people delay ovulation until 20 to 44 hours after the urinary LH peak.

5.Ultrasound to see follicles

The so-called B-ultrasound follicle monitoring is generally a vaginal B-ultrasound, which is of great significance in the treatment of infertile patients. When should follicle monitoring be done? Generally, starting from the 8th day of the menstrual cycle, B-ultrasound monitoring is performed once every 2 days. When the diameter of the follicle is found to be 17 mm, monitoring should be changed to once a day. When the follicle matures and reaches a diameter of 20-23 mm, it should be measured twice a day if necessary until ovulation.

6. Record ovulation bleeding

Ovulation bleeding is similar to ovulation pain and is an ovulation indicator that only a small number of people experience. In the middle of the menstrual cycle, which is the ovulation period, estrogen reaches its highest value before the luteinizing hormone peak, and then drops rapidly. For some people, the dropped estrogen level cannot maintain the growth rate of the endometrium, causing local ulceration and shedding of the surface layer of the endometrium, and a small amount of breakthrough bleeding occurs, which we call ovulation bleeding. It usually occurs later in the day of ovulation or on the second or third day.

Not everyone experiences ovulation bleeding, and not everyone who has experienced it will experience it in every menstrual cycle. Therefore, it is rather mysterious to use it to monitor ovulation. Like ovulation pain, it is only an auxiliary method. Moreover, when most people bleed, they have already ovulated or even the egg that has been discharged is past the time for conception. We can record the time of mid-term vaginal bleeding for confirmation while taking B-ultrasound and basal body temperature.

7. Ovulation pain

As a means of monitoring ovulation, ovulation pain is also a very specific indicator. However, survey data show that the proportion of people who clearly feel ovulation pain is around 37%.

The pain feels like a cramp or side stitch. Most of the pain occurs in the left and right lower abdomen. Some people feel pain above the pubic bone, and some people feel a pain in the anus. Sensitive people can feel it the day before ovulation. The pain intensifies during ovulation and lasts for 2 to 6 hours. For some people, it can last up to more than ten hours. Generally speaking, even if ovulation pain is not easy to detect, most people can feel it if they pay attention to themselves. If you combine ovulation pain with B-ultrasound, basal body temperature, and cervical mucus, you can grasp the ovulation date more accurately.