Understanding Your Fertility Hormones: LH, Estrogen & Progesterone

Your menstrual cycle is like a perfectly choreographed dance controlled by hormones. Understanding the main players—Estrogen, Luteinizing Hormone (LH), and Progesterone—can key you into identifying your fertile window and spotting potential issues.

1. Estrogen: The Builder

At the start of your cycle (Follicular Phase), estrogen levels rise. Think of estrogen as the "builder." It thickens the uterine lining to prepare a cozy bed for a potential pregnancy.

• **Sign:** As estrogen peaks just before ovulation, you'll see "fertile" cervical mucus that looks like uncooked egg whites.

2. Luteinizing Hormone (LH): The Trigger

Once estrogen reaches a certain level, it signals your brain to release a massive surge of LH. This "LH surge" is the trigger that causes the ovary to release an egg (ovulation).

3. Progesterone: The Sustainer

After ovulation, the empty follicle turns into the corpus luteum and starts pumping out progesterone. This hormone stabilizes the uterine lining and warms your body up.

• **Sign:** This is why your Basal Body Temperature (BBT) rises after ovulation. If you get pregnant, progesterone stays high. If not, it drops, triggering your period.

The Big Picture

Tracking these changes—mucus (Estrogen), OPKs (LH), and Temperature (Progesterone)—gives you a complete 360-degree view of your fertility health.