Spotting or bleeding between periods is common, and it usually has a simple cause. But it’s also one of the signs doctors want to hear about. Here’s what causes it, and when to get it checked.
Bleeding between periods means any bleeding or spotting between periods, outside your normal menstrual flow. It can be a few pink or brown spots or a light flow. Common causes include ovulation, hormonal birth control, early pregnancy and perimenopause, but polyps, fibroids and infection can also cause it. Doctors classify it as abnormal uterine bleeding, so it’s worth mentioning to your doctor, especially if it keeps happening, comes after sex, or appears after menopause.
When to see a doctor
Make an appointment if:
- You’ve had bleeding between periods in two or more cycles.
- You bleed after sex.
- You have any bleeding after menopause (12 months with no period). This always needs a check.
- Bleeding comes with pelvic pain, pain during sex, fever, or unusual or bad-smelling discharge.
- You’re 45 or older and your bleeding pattern has changed.
- You could be pregnant, or you have a positive pregnancy test.
- You’re behind on cervical screening.
Seek urgent care for heavy bleeding (soaking a pad or tampon every hour for two hours), fainting or dizziness, severe pain, or bleeding in pregnancy with one-sided pain or shoulder pain.
Common causes of bleeding between periods
Hormone-related
- Ovulation spotting. Light spotting for a day or two mid-cycle, about two weeks before your next period, as hormones shift around ovulation. See How to Know If You’re Ovulating.
- Hormonal birth control. Breakthrough bleeding is common with the pill, patch, ring, implant, shot and hormonal IUD, especially in the first three to six months, after missed pills, or with low-dose pills. A copper IUD can also cause spotting at first.
- Emergency contraception, which can cause unexpected bleeding within a few weeks.
- Irregular ovulation, for example with PCOS (now called PMOS), thyroid problems, big weight changes or stress.
- Perimenopause. In your 40s, hormone swings make spotting and irregular periods more common. New or heavy bleeding still needs a check.
Pregnancy-related
- Implantation bleeding, light spotting around the time your period is due.
- Early miscarriage or ectopic pregnancy, which need prompt care. If you could be pregnant, take a test.
Changes in the uterus or cervix
- Polyps, small growths in the uterine lining or on the cervix. Usually benign, and a common cause of bleeding between periods and after sex.
- Fibroids, benign muscle growths that can cause spotting and heavier periods.
- Adenomyosis or endometriosis, often with painful periods.
- Cervical ectropion, a harmless area of delicate cells on the cervix that can bleed after sex.
Infection
- Cervicitis or sexually transmitted infections such as chlamydia or gonorrhea, which often cause bleeding after sex and may have no other symptoms.
- Pelvic inflammatory disease, usually with pelvic pain or fever.
Other causes
- Medicines such as blood thinners, and some supplements.
- Less commonly, thickening of the uterine lining (endometrial hyperplasia) or cancer of the cervix or uterus. These are uncommon, especially in younger women, but they are the reason persistent bleeding should be checked, not watched.
Spotting before your period vs between periods
Timing helps. Spotting in the day or two right before your period is often just the period starting slowly; see Spotting Before Your Period: Normal or Not? Bleeding well away from your period, especially mid-cycle without a clear pattern or after sex, is the kind doctors most want to hear about.
Brown spotting between periods is usually older blood that took longer to leave the body. The color alone doesn’t tell the cause.
If it’s your period itself that keeps going, past 7 days or longer than it used to, see Period Lasting Longer Than Usual?
What your doctor may check
- Questions about your cycle, birth control, sex and any medicines.
- A pregnancy test.
- A pelvic exam and, if due, cervical screening.
- Tests for infection.
- Blood tests, such as blood count and thyroid.
- A pelvic ultrasound to look for polyps or fibroids.
- Sometimes a small sample of the uterine lining, more often after age 45 or with risk factors.
Most causes are found with these simple steps, and most are treatable.
Track it before your appointment
For two or three cycles, note:
- the dates of your periods and of any bleeding between them
- how much (spots, light, needs a pad) and the color
- whether it came after sex, exercise or a missed pill
- any pain, discharge or other symptoms
Don’t wait for a pattern if you have any of the warning signs above.
The traditional Chinese medicine view
Traditional Chinese Medicine calls bleeding between periods jing jian qi chu xue and describes it in a few patterns. Light mid-cycle bleeding with dryness, warmth at night or restlessness is often described as Kidney yin deficiency with heat. Sticky discharge with bleeding may be described as damp-heat, and bleeding with pale skin and tiredness as Spleen Qi too weak to hold the blood. These are traditional descriptions, not a diagnosis, and the medical checks above come first.
Once other causes are ruled out
If your doctor finds no structural cause or infection, and the bleeding is part of a cycle that also runs early, late or unpredictably, CycleBalance is one option to discuss. It is a sealed herbal pouch worn over the navel, held by a reusable belt and replaced every five days. It does not treat polyps, fibroids, infection or any other cause of bleeding, and it is not a substitute for being checked. There are no controlled studies of it, and no practice records specific to bleeding between periods are presented here.
See CycleBalance’s directions →
Quick answers
Is bleeding between periods normal?
Occasional light spotting, for example around ovulation or with new birth control, is common. Bleeding that repeats, follows sex, or happens after menopause should be checked.
Can stress cause bleeding between periods?
It can, by disrupting ovulation and hormones. It’s still worth ruling out other causes.
Why am I bleeding between periods on the pill?
Breakthrough bleeding is common in the first few months, after missed or late pills, or with some low-dose pills. If it continues past three months or is new on a pill you’ve used for a long time, see your prescriber.
Reviewed October 2026. Author: Qingcai Wang, MD, PhD, developer of the Five Essences external herbal-pouch formulations, with a commercial interest in their sale. General education only; continue your medical care.
Sources: American College of Obstetricians and Gynecologists, Abnormal Uterine Bleeding; Abnormal Uterine Bleeding, StatPearls (2025).
The routine behind this article
CycleBalance is the Five Essences external herbal pouch matched to this topic — worn on the body, nothing swallowed. One course is six pouches (about 30 days), with a fresh pouch every five days. $199 per course; the reusable belt is $15 if you don’t have one. Every first course is covered by the 90-Day First-Course Satisfaction Guarantee.
Wellness support, not medical care.
This article is part of our Women’s Core Health guide — cycle, fertility and postpartum, in one place.