Spotting Before Expected Period: Implantation Bleeding, Hormonal Causes, Perimenopause, and Pathologic Concerns

Premenstrual spotting (light bleeding before expected menses) has several etiologies:

1. Implantation Bleeding

• 6–12 days post-ovulation (DPO); light pink/brown spotting, few hours–2 days.
• Not all pregnant women experience it (~25–30%).

2. Luteal Phase Defect / Low Progesterone

• Inadequate endometrial stabilization → premenstrual spotting.
• Associated with short luteal phase (<10 days).

3. Hormonal Contraception

• Breakthrough bleeding on OCPs (especially low-dose, extended-cycle), implants, IUDs (copper/hormonal).
• Emergency contraception (levonorgestrel) → withdrawal bleed.

4. Ovulation Spotting

• Mid-cycle (day 10–16); brief, due to estrogen dip.

5. Perimenopause (40s–50s)

• Erratic follicular recruitment → estrogen fluctuations → irregular shedding.

6. Structural / Pathologic

• Cervical polyp / ectropion (postcoital spotting).
• Endometrial polyp / submucosal fibroid.
• Endometritis / cervicitis (STI: chlamydia, gonorrhea).
• Endometrial hyperplasia / carcinoma (especially >45 or risk factors).

Action Plan

1. Pregnancy test (urine hCG) if sexually active.
2. Track pattern (timing, duration, volume, associated symptoms).
3. See gynecologist if: persistent >3 cycles, heavy, postcoital, postmenopausal, or with pain/fever.