A woman’s body works according to a certain cycle, with a 2-day special fertile window. These two special days are the period of the woman’s maximum levels of fertility, when she has the highest chances to get pregnant.
Many women experience ovulation around the day 14 of their cycle. However, this is not an established rule for every woman, and due to a number of reasons this process of ovulation can also take place earlier or later for different women. Therefore, this is one important reason why women go for ovulation tests, in order to chart one’s fertility levels.
Ovulation Tests are excellent tools for prediction of a woman’s most fertile time during her monthly cycle. These tests work by detecting the LH levels in urine. Just before ovulation, women experience a sudden and dramatic rise in the levels of luteinizing hormone (LH). We call this rise as “LH surge”.
Detection of the LH surge can predict when you can ovulate. The most fertile time of your cycle ranges in between the next 2-3 days beginning your surge, with a peak fertility level reaching during the first 36 hours.
Getting intimate during this time has the maximum chances of you being pregnant. Therefore, timing is one of the most important factors, while one is trying to conceive.
To determine when to start testing, you should do a little calculation first. Begin by determining the average length of your normal cycle, which could vary anywhere between 20 to 45 days. Start counting from the first day of your period (i.e. the first day of bleeding and spotting) and stop the count on the first day of your next period. This becomes the length of your cycle. If this length is different each month by more than just a few days, then simply go with the average number of days over the last three months.
Once you determine the average number of days for the length of your cycle, and then refer to the cycle chart to determine which day of your cycle you should begin testing.
A menstrual cycle has three phases. Each phase produces different hormones with distinct set of functions. The first is the follicular phase that begins on the Day one of the cycle. The first day is the full day of your menstrual bleeding when the uterine lining begins to shed. If the egg fertilization does not happen during the previous cycle, the body must shed the lining of the uterus to prepare itself for the next cycle. This phase lasts for 3-5 days, but can be even more or less.
Immediately following the shedding of uterus lining, the body begins to prepare for the cycle’s next phase, the ovulatory phase. However, before this phase begins, the hormones prepare the body for ovulation. The pituitary gland releases two hormones, Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH). The FSH stimulates a follicle to grow and the inside egg to ripen. LH stimulates the follicle to manufacture and secrete estrogen.
When the estrogen amount reaches a certain level, it causes the pituitary gland to release LH surge. 24-36 hours post the LH surge, the follicle bursts, releasing the completely ripened egg into the fallopian tube. This egg release is what we term as ‘Ovulation’.
The redeemed egg now floats down the fallopian tube, making its way towards the womb. If the fertilization of egg is not complete, it will survive for not more than 24 hours. The day of ovulation and the one before it are the two most fertile days of a woman’s cycle, when the chances of her getting pregnant are the highest. LH surge always precedes ovulation so detection of this hormone is significant for the prediction of the two special days.
The final phase of your menstrual cycle is the ‘luteal phase’. It follows ovulation. In case of egg fertilization, the body produces hCG that any pregnancy test can easily detect.
The follicle, where the egg bursts, starts shrinking and releasing progesterone and estrogen. Progesterone prepares for the fertilized egg, by building the uterine lining with the increase in blood vessels. The increase in the production of progesterone maintains the pregnancy. hCG hormone assists in continuing the production of progesterone and estrogen.
In case, the egg fertilization does not take place within 24 hours, the production of progesterone declines gradually. When there is not enough progesterone, after around 11-14 days, the menstrual cycle begins again.