Intermenstrual Bleeding (IMB)
Intermenstrual bleeding is bleeding or spotting that happens between two true periods. It can be one day of light spotting or several days of flow.
Fertility charting makes the pattern visible, because the day, the color, and the length are all written down. A normal cycle runs 24 to 38 days with up to eight days of bleeding, and classification systems sort bleeding outside that pattern by cause.1 A polyp, a fibroid, chronic endometritis, low progesterone, or a thyroid problem can each be the reason.
Spotting near ovulation was a less specific sign of ovulation than mid cycle pain in early charting research.2
Cited in this entry
- Jain V, Munro MG, Critchley HOD. Contemporary evaluation of women and girls with abnormal uterine bleeding: FIGO Systems 1 and 2. International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics. 2023. https://pubmed.ncbi.nlm.nih.gov/37538019/
- Hilgers TW, Daly KD, Prebil AM, Hilgers SK. Natural family planning III. Intermenstrual symptoms and estimated time of ovulation. Obstetrics and Gynecology. 1981. https://rrmacademy.org/library/natural-family-planning-iii-intermenstrual-symptoms-and-estimated-time-of-ovulat-recefanxhpre7oxto/
This content is for educational purposes only and does not constitute medical advice. Consult an RRM clinician or healthcare provider for guidance specific to your situation.
