Fertility Tracking 101: Understanding Your Biomarkers

Fertility awareness-based methods (FABM) help you map your fertile window by observing physiological markers.

#### Primary Biomarkers to Monitor

• Basal Body Temperature (BBT): Your body temperature at rest immediately upon waking. Progesterone causes a thermal shift (about 0.5°F - 1°F rise) post-ovulation.
• Cervical Mucus (Fluid): Estrogen causes cervical mucus to change from dry/sticky to creamy, and finally to clear, stretchy, and slippery (resembling raw egg whites) during your fertile window.
• Luteinizing Hormone (LH): Urinary surges of LH precede ovulation by 24–36 hours and can be detected using ovulation predictor kits (OPKs).

#### Phases of the Cycle

1. Follicular Phase: Estrogen rises, leading to cervical fluid production.

2. Ovulatory Phase: LH surge triggers follicle release.

3. Luteal Phase: Progesterone dominates, raising BBT and drying cervical fluid.