Spotting between periods — light bleeding that occurs outside of your normal menstrual cycle — is relatively common and has many possible causes, ranging from benign hormonal changes to conditions that need medical attention. 1 While occasional mid-cycle spotting is often normal, persistent or unexplained intermenstrual bleeding should always be discussed with a healthcare provider.
For related concerns about cycle irregularity, see our guide to irregular periods causes and when to see a doctor.
What Counts as Spotting vs. a Period
Spotting refers to light, irregular bleeding that is not a full menstrual period. It typically does not require a pad or tampon and may appear as small spots of blood in underwear or on toilet paper. A normal period involves a heavier, more predictable flow that follows the typical 21–35 day menstrual cycle and lasts 2–7 days.
The distinction matters because spotting and irregular menstrual periods can have different underlying causes. 1
Common Causes of Spotting Between Periods
Ovulation Spotting
Light spotting around the midpoint of the menstrual cycle — approximately day 14 in a 28-day cycle — may occur at the time of ovulation. A brief drop in estrogen associated with the LH surge can trigger slight uterine lining shedding. 2
Hormonal Contraceptives
Breakthrough bleeding or spotting is very common during the first 3–6 months of starting hormonal birth control, including the pill, patch, ring, or hormonal IUD. The uterine lining adjusts to lower and more stable hormone levels. 1
Implantation Bleeding
When a fertilized egg implants into the uterine lining — typically 6–12 days after conception — light spotting may occur. Implantation bleeding is usually lighter than a period, shorter in duration, and may be accompanied by mild cramping. A pregnancy test can confirm or rule out pregnancy if implantation bleeding is suspected.
Cervical Irritation
The cervix has a rich blood supply and can bleed easily when irritated. Spotting after sexual intercourse (postcoital bleeding) or after a Pap smear is commonly caused by cervical irritation or cervical ectropion — a condition where cells from inside the cervical canal are present on the outer cervix. 3
Perimenopause
During the perimenopausal transition — which can begin in the early to mid-40s — hormonal fluctuations become erratic, causing irregular cycles and unpredictable spotting. Periods may become lighter, heavier, shorter, or longer. 2
Less Common but Important Causes
Some causes of intermenstrual spotting require prompt diagnosis and treatment:
Uterine fibroids: Benign smooth muscle tumors in the uterus are a very common cause of heavy periods and may also cause spotting. They affect up to 70–80% of women by age 50. 3
Endometrial or cervical polyps: Small, usually benign growths on the uterine lining or cervix that can cause irregular spotting.
Polycystic ovary syndrome (PCOS): Hormonal imbalance and irregular ovulation associated with PCOS can lead to unpredictable bleeding patterns.
Thyroid disorders: Both hypothyroidism and hyperthyroidism can disrupt menstrual regularity and cause abnormal bleeding.
Sexually transmitted infections (STIs): Infections such as chlamydia and gonorrhea can cause cervical inflammation and spotting, particularly after intercourse.
Endometriosis: Tissue similar to the uterine lining growing outside the uterus can cause irregular bleeding alongside pelvic pain.
Cervical or uterine cancer: While less common, cancer of the cervix or endometrium can cause irregular or postcoital bleeding. 4
Medications and Lifestyle Factors That Cause Spotting
Beyond contraceptives, other medications and lifestyle factors associated with intermenstrual spotting include:
- Blood thinners such as warfarin or aspirin
- Emergency contraception (the morning-after pill), which commonly causes spotting
- Certain antidepressants that affect estrogen metabolism
- Significant stress, which can disrupt the hypothalamic-pituitary-ovarian axis and alter cycle regularity
- Extreme weight loss or gain
- Excessive exercise or low body weight, which can suppress ovulation and cause irregular bleeding1
Tracking and Evaluating Spotting
Keeping a record of spotting episodes — including date, amount, color, associated symptoms, and relationship to the menstrual cycle — helps your provider identify patterns. Cycle-tracking apps can be useful tools for this purpose.
For evaluation, your doctor may recommend:
- Pelvic examination
- Pap smear and STI testing
- Pelvic ultrasound to visualize the uterus and ovaries
- Hormonal blood tests (FSH, LH, estrogen, thyroid)
- Endometrial biopsy if postmenopausal or at risk for endometrial cancer4
When to See a Doctor
Contact your healthcare provider or gynecologist if:
- Spotting occurs regularly between periods without a clear cause
- You experience postcoital bleeding (spotting after sex)
- Any bleeding occurs after menopause
- Spotting is accompanied by pelvic pain, pressure, or unusual discharge
- You have a positive pregnancy test alongside spotting
- Spotting is heavier than usual, lasts more than a few days, or appears bright red
In younger women, one or two isolated episodes of light mid-cycle spotting without other symptoms may not require urgent evaluation, but a pattern of recurrent intermenstrual bleeding always warrants assessment.
Frequently asked questions
Is it normal to spot between periods?
Occasional light spotting — particularly around ovulation or during the first months of hormonal contraception — is common and usually benign. Persistent, recurring, or unexplained spotting between periods should be evaluated by a healthcare provider.
What does implantation bleeding look like compared to spotting?
Implantation bleeding is typically very light, pinkish or brownish in color, and lasts only 1–3 days. It occurs roughly 6–12 days after conception. Unlike a period, it does not progress to heavier flow. A home pregnancy test after a missed period can confirm whether implantation has occurred.
Can stress cause spotting between periods?
Yes — significant physical or emotional stress can disrupt the hormonal axis that regulates menstruation, leading to irregular cycles and intermenstrual spotting. However, stress is a diagnosis of exclusion; other causes of spotting should be evaluated before attributing it to stress alone.
What color is spotting between periods?
Spotting can range from light pink (fresh, minimal blood) to dark brown (older blood that has taken time to exit the uterus). Bright red spotting may indicate more active or heavier bleeding. The color alone is not diagnostic but can provide contextual clues.
Can a hormonal IUD cause spotting between periods?
Yes — irregular spotting is very common in the first 3–6 months after hormonal IUD insertion as the uterine lining adjusts to lower, localized progesterone levels. For many users, periods become lighter or stop altogether over time. Persistent heavy bleeding or pain after IUD insertion should be evaluated.