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Can LH Surge Happen Before Your Period?

Can LH Surge Happen Before Your Period?

Testing for an LH Surge can help predict your fertility window and determine when you are ovulating. Generally, physicians in Australia recommend testing LH in the first half of your cycle or the follicular phase. However, there is merit in continuing to test for LH even after ovulation.

You might assume that the level of LH falls back to the baseline once you ovulate. But did you know that it is common for some women to experience an additional increase in LH after the initial surge? The second peak in LH occurs before the period starts.

In the rest of this piece, we will look at these additional LH surges before your periods and what they mean. We will also explore the reason behind this phenomenon and try to understand what happens to the LH level throughout your period. So, let’s get going!

Can you get a positive ovulation test right before your period?
Can you get a positive ovulation test right before your period?

How common is it to have an LH surge before your period?

Having multiple LH surges during the menstrual cycle is quite common. According to a study conducted on 107 women, 33% had two peaks of LH during their menstrual cycle, 8% had multiple peaks, and 11% of women experienced an LH plateau after the initial surge.

Although almost 48% of women in the study had a single peak during their menstrual cycle, the study offers a good insight into the differences in LH peaks in different women.

Why is there an LH surge before your period?

Scientists have more than one explanation for some women experiencing multiple LH surges. One of the most widely accepted explanations among Australian physicians is that when the progesterone level in your blood drops drastically at the end of the luteal phase of the menstrual cycle, it triggers LH release. It is also possible that a small amount of LH is released after implantation of the embryo in the uterine wall.

Another possible explanation is if you naturally have a higher baseline level of LH, then any small fluctuation can yield a higher-than-average result in the LH test. You might be misled to believe that there has been an additional LH surge.

Can LH surge before your period prevent you from being pregnant?

No. It is quite possible to conceive even if your LH test shows that your levels are surging. Remember, LH can be released once the implantation occurs, so there is no reason to worry if you find that your LH levels are surging even after you ovulate. It most likely won’t prevent you from getting pregnant.

Why is my LH high before period due?
Why is my LH high before period is due?

How do LH levels look throughout your cycle?

Although the LH levels amongst women can vary greatly, certain numbers are considered ‘normal.’ Here is how your LH levels wax and wane throughout the different phases of your menstrual cycle.

But before we go ahead, we would like to clarify that the normal ranges of LH are taken from Mayo Clinic Laboratories. It would be best to remember that different laboratories might slightly vary their numbers.

Baseline LH levels

The typical baseline level of LH is between 0.7 to 14.6 IU/L. During the first 14 days of the menstrual cycle (also called the follicular phase), the LH measures around  1.9 IU/L to 14.6 IU/L, while it slightly dips to  0.7 to 12.9 IU/L during the last 14 days of your cycle (luteal phase).

However, the baseline LH levels between 5-15 IU/L for most women are considered normal.

Lowest LH levels

You might experience the lowest LH levels during the luteal phase if you have a regular menstrual cycle. During this phase of your cycle, it is common to see the LH ranges hovering between 0.7 to 12.9 IU/L. In pregnant women, however, the level of LH can be significantly lower, being as low as below 1.5 IU/L.

Highest LH levels

The highest levels of LH are recorded about 24-36 hours before you ovulate. Generally referred to as an ‘LH surge,’ the normal range is anywhere between 12.3 to 118 IU/L.

It is common to see elevated baseline LH levels between 5.3 to 65.4 IU/L if you are going through menopause.

FAQs regarding LH surge

What are the symptoms, if any, of an LH surge?

It is not common to experience any significant symptoms of LH surge. However, some omen might experience physical symptoms during the LH surge before ovulation. Some of the most common signs of an LH surge include the following-

  • Slight pain in the abdominal region also called “mitt
  • Tenderness of the breast or breast pain
  • Slight spotting or spotting
  • Increased secretion of cervical mucous and change in consistency to ‘egg white.’
  • Increased basal body temperature

How long does an LH surge last?

Typically, an LH surge lasts for about 24-36 hours. You should remember that the physiology of every woman is different, and there can be significant changes in these numbers. Also, the duration of an LH surge can vary between cycles. So, in one cycle, it might be 24-36 hours, and in another, it can be significantly lower or higher.

What is the best way to test LH surge?

You can use several ways to keep track of your LH surges. Some of the most popular methods to do it include the following-

  • Tracking your period and physical symptoms that come along
  • Using ovulation predictor kits like the high quality, accurate and affordable midstream and stripe kits from Fertility2Family
  • Using a basal body temperature thermometer that can accurately measure your body temperature to determine LH surges
  • A blood test in your doctor’s office

The criterion for the best test can be very individualistic, and what is best for you depends on your situation and your pregnancy goals. For instance, merely tracking your physical symptoms to determine the LH surge might not be the best idea if you are trying to conceive.

You might want to use ovulation prediction kits like those available at Fertility2family, which make monitoring LH surges quite easy. Knowing when your LH surge occurs can be a great bit of information to have if you want to conceive as quickly as possible.

If you are struggling to get pregnant or have some health conditions like polycystic ovarian syndrome (PCOS), it might be best to get the LH levels tested at your doctor’s office. Knowing the same LH levels might help your doctor suggest potential solutions to your problem.

If you are trying to conceive, the best method is to use various methods. Use ovulation prediction kits to determine your LH surge and hence ovulation window while maintaining a journal of all the physical symptoms that you might be experiencing. Using multiple methods to track LH surges might help you predict your fertility window. Doing this can help you track your hormones and help you understand your body better, and stay in tune with it.

What are the chances of getting pregnant during LH surge?
What are the chances of getting pregnant during an LH surge?

How often should I test for LH?

If you want to get the most information out of testing for LH, you should maintain a regular schedule. It is recommended that you test your LH levels every day, starting 5 to 7 days before your estimated ovulation date. If you are unsure when you ovulate, it is good to start testing early in the cycle to minimize missing out on the surge when it happens. For most women who don’t know when they will be ovulating, beginning around the 6th day of your cycle is best.

Once you spot the spike in the LH levels, ovulation is imminent. For most women, ovulation occurs within 24-36 hours of LH surge. If you are trying to conceive, this is the best time to have sex with your partner as your fertility window starts 24-36 hours before ovulation and continues three days after you ovulate. Once you ovulate, it is unnecessary to keep tracking your LH throughout the rest of your cycle.

If you consistently track your LH and ovulation, you can have a solid idea about your fertility window. It might take a few months before you gather enough information to make any predictions, so be patient.


LH is a crucial hormone that helps your ovaries release the egg once it is matured. Knowing when your LH surge occurs can help you identify your fertility window and start making efforts to get pregnant.

Although the levels of LH might keep fluctuating throughout your cycle, it is the initial surge that provides the most crucial information. Don’t be alarmed if you have two or more LH peaks during your cycle. It is common in some women to see multiple LH peaks, and it has little to no effect on your chances of getting pregnant.