Implantation Bleeding: Timing, Appearance, and Differential

Implantation bleeding occurs when the blastocyst attaches to the endometrium, typically 6–12 days post-ovulation (peak 8–10 days).

Typical Features

• Light spotting (pink/brown), not heavy flow
• Lasts hours to 1–2 days
• No clots
• May accompany mild cramping

Day 17 of Cycle (Assuming 28-day Cycle)

Ovulation ~day 14 → day 17 = 3 days post-ovulation. Too early for implantation bleeding.

Other Causes of Mid-Cycle Spotting

• Ovulation bleeding (estrogen drop)
• Hormonal contraception breakthrough
• Cervical polyp/ectropion
• Infection (cervicitis, STI)
• Endometriosis
• Perimenopause

Recommendation

Track cycles; if spotting recurs or is concerning, consult OB/GYN for exam and possible ultrasound/hormone testing.