Why spotting between periods happens and when to be concerned

Bleeding or spotting between regular monthly periods can be alarming. When this happens, you may see just a small amount – a spot or two of blood – on your underwear or toilet paper, or the amount may seem like you've started your period.

Patients often ask me about spotting between periods, or breakthrough bleeding. While it's not usually a concern, spotting can sometimes indicate a more serious issue that needs treatment.

Normal periods

Normal menstrual bleeding lasts about five to seven days. While periods typically occur every 28 days, anywhere from 21 to 35 days between periods is considered normal. About 14 days after your period starts, you ovulate and release an egg from the ovary. Spotting during ovulation, which is usually light and lasts one to two days, is normal, but it should be discussed with your doctor. The uterine lining is ready for the implantation of a fertilized egg, and there can be what's called implantation bleeding if that occurs and pregnancy begins.

What conditions might cause someone to bleed between periods?

Bleeding between menstrual cycles can result from structural issues within the uterus, such as endometrial polyps or uterine fibroids. Polyps are small, abnormal tissue growths that can occur in a number of places including the cervix and uterus. Most polyps are benign, or noncancerous.

Spotting can also be due to sexually transmitted infections like gonorrhea or chlamydia, which typically infect the cervix. Learn the symptoms of sexually transmitted infections and contact your doctor if you suspect you have one.

Birth control 

Hormonal birth control methods, including pills, patches, injections, rings and implants, can all cause spotting between periods.

• Birth control pills: Some women on the birth control pill may experience irregular bleeding if pills are missed.
• Injections: Women who use the Depo-Provera injection as their birth control method may experience irregular cycles or bleeding between cycles as a side effect of the medication.
• Hormonal IUD: Women who have a hormonal IUD in place may also experience irregular bleeding. However, this typically resolves itself within the first several months after placement. 

Switching hormonal birth control methods can temporarily alter your progesterone hormone levels, which could lead to spotting. As your system gets used to your new contraception, the spotting should stop.

When should a woman consider seeing her doctor?

If you've been spotting consistently for several months or you’re worried about abnormal vaginal bleeding for any reason, keep a menstrual diary to track irregular menstrual cycles or bleeding. If the irregularity persists for more than two months, consider making an appointment to see your ob/gyn for a pelvic exam.