HealthcareProgramsEbooks

Hormones in Week 2: Oestrogen, LH Surge, and Egg Release

ByDiwanshu Dika
Updated: 4 Feb 2026, 12:30 pm
Medically Reviewed by Dr. Astha Gupta, Director – Reproductive Medicine & IVF, Cloudnine Hospital

Week 2 of the menstrual cycle is driven by powerful hormonal changes that lead to ovulation. Rising oestrogen levels, a sudden luteinising hormone (LH) surge, and the release of a mature egg work together to create the fertile window. Understanding these hormonal shifts in week 2 helps explain how the body prepares for possible conception.

Pregatips.com
istock
Week 2 of the menstrual cycle is an essential time because your hormones are actively at work behind the scenes. This week, oestrogen levels rise, the luteinising hormone (LH) surges, and the ovary releases a mature egg. These changes happen quietly, but they decide whether pregnancy can occur in that cycle. Many people experience minor changes in their bodies during this time, but do not always know what is causing them.
In this article:
Therefore, you should understand what your hormones do in week 2. It helps you recognise your fertile days, plan for pregnancy if you are trying to conceive, and feel less confused about your body’s changes.

Let’s understand the importance of these hormones and how they help with successful conception.



Why are Oestrogen, Luteinising Hormone, and Egg Release Important for Fertility?

Hormones in week 2 work together to create the right conditions for conception. When oestrogen, the LH surge, and egg release function correctly, they support every step needed for fertilisation and early pregnancy. Here’s why these hormones are essential for fertility.

  • Timing ovulation correctly
Oestrogen rises and signals the brain, while luteinising hormone triggers the release of the egg. The precise timing allows the ovary to release a healthy egg at the right moment. When this process stays balanced, the chances of conception improve. If the timing shifts, ovulation may become irregular or fail to occur.

  • Preparing the uterus for implantation
Oestrogen thickens the uterine lining and makes it ready to support a fertilised egg. A well-prepared lining helps the egg attach and grow in the early days of pregnancy. Without proper hormonal support, implantation becomes difficult.

  • Supporting sperm movement and survival
Oestrogen changes cervical mucus into a fertile form that allows sperm to move easily. This change protects sperm and helps them live longer inside the body. As a result, sperm have more time to meet the egg and fertilise it.

  • Defining the fertile window
These hormones clearly signal the most fertile days of the cycle. Knowing this window helps people time intercourse better and understand when pregnancy is most likely to happen.

How Do Oestrogen, the LH Surge, and Egg Release Work Together in Week 2?

Hormones work in a precise sequence during week 2 to make ovulation possible. Each hormone plays a specific role, and together they prepare the body for potential fertilisation. Here’s how oestrogen, LH, and egg release work together in week 2.

  • The Role of Oestrogen in Week 2
Oestrogen levels rise steadily during week 2 as follicles in the ovaries develop and mature. This hormone prepares the body in several important ways. It thickens the uterine lining, enabling it to support a fertilised egg if conception occurs. Oestrogen also changes the texture of cervical mucus, making it thinner and more slippery. Thus, the change allows sperm to travel more easily through the reproductive tract. At the same time, rising oestrogen sends signals to the brain that the body is approaching ovulation and is ready to release an egg.

  • LH Surge
When oestrogen reaches its highest level, it triggers a response in the brain. The pituitary gland releases a sudden surge of luteinising hormone (LH). The LH surge is essential because it directly tells the ovary to release the mature egg. Ovulation usually happens within 24 to 36 hours after this surge. Many ovulation predictor kits work by detecting this hormone rise, which is why they help identify the most fertile days.

  • Egg Release and the Fertile Window
After the LH surge, the ovary releases a mature egg into the fallopian tube. The egg can survive only 12 to 24 hours, making timing very important. However, sperm can live in the female reproductive tract for up to five days. Because of this difference, the fertile window includes the days before ovulation as well as the day ovulation occurs.

What to Do Next?

  • Track your menstrual cycle regularly to understand your ovulation pattern.
  • Observe physical signs such as cervical mucus changes or mild ovulation pain.
  • Use ovulation predictor kits if you are trying to conceive.
  • Maintain a balanced diet and stay well hydrated to support hormonal health.
  • Manage stress and prioritise quality sleep to keep hormones balanced.
  • Consult a healthcare professional if your cycles are irregular or if ovulation signs are unclear.
Week 2 is a hormonally active phase that sets the stage for possible pregnancy. Rising oestrogen prepares the body, the LH surge triggers ovulation, and the ovary releases a mature egg. Knowing these hormonal changes may help you gain clarity about your fertile window and feel more confident managing your reproductive health.

You’re not alone in your journey when trying to conceive. Join our supportive community to connect with others, share experiences, and find encouragement every step of the way.

FAQs on Hormones in Week 2: Oestrogen, LH Surge, and Egg Release


  1. Can ovulation happen without an LH surge?
    No. Ovulation depends on the LH surge to release the egg.
  2. How long does the egg survive after release?
    The egg survives for about 12 to 24 hours after ovulation.
  3. Can I get pregnant before ovulation?
    Yes. Sperm can survive up to five days, so that pregnancy can occur from intercourse before ovulation.

Related Stories

  1. Hormones in Week 2: Oestrogen, LH Surge, and Egg Release
  2. How to Confirm Pregnancy at Home: Easy Methods You Can Trust
  3. Why You Cannot Test Positive in Week 1: The Science, Timelines, and What to Do Instead
  4. Light Bleeding in Week 1: Why It Does Not Automatically Mean Pregnancy
  5. Why Sperm Wait for the Right Temperature to Fertilise
  6. Understanding FET: How Frozen Embryos Can Help You Conceive
How we reviewed this article
Our team continuously monitors the health and wellness space to create relevant content for you. Every article is reviewed by medical experts to ensure accuracy.