Spotting may occur in the beginning or very end of your period and often is blushy pink. Some women also notice spotting on their ovulation day. Spotting or intermenstrual bleeding may have various underlying reasons. Sometimes, it can be a sign of a serious problem, but it’s often nothing to worry about.

Hormonal birth control (including patches, injections, pills, rings, and implants) can cause spotting if you’re using them for the 1st time, not taking the pills correctly, changing the type or dose of your hormonal contraceptives, or using any of the methods for too long.

Ovulation. About 3% of women have ovulation-related spotting that occurs around the time in your menstrual cycle when your ovary releases an egg. It may last for 1-2 days and be accompanied by other symptoms of ovulation.

Implantation bleeding. When a fertilized egg attaches to the inner lining of your uterus, you may experience scant implantation bleeding. Or you may not.  

Implantation spotting usually occurs a few days before your next period and is much lighter in flow and shorter in duration than your usual period. The discharge in this case is usually light pink to dark brown in color.

Pregnancy. About 15-25% of women may have spotting in the first trimester.  It is not usually a reason for concern, but inform your ob-gyn that it is happening. If you’re pregnant and additionally experience pain or heavy bleeding, see your doctor immediately.  

Perimenopause. Women who are approaching menopause may also experience intermenstrual bleeding due to hormonal changes.

Stress. As it affects your hormones, stress can also lead to other changes in your menstrual cycle. Some women may have intermenstrual spotting due to high levels of physical or emotional stress.

If you notice spotting other than before your period, there may be some other possible reasons for it.

• Irritation after sexual contact

• Postpartum blood discharge or lochia

• Polyps

• Endometriosis

• Fibroids

• PCOS

• Certain meds

• Thyroid problems, such as underactive thyroid

• Cancer of the female reproductive organs

• Injuries

• Ectopic pregnancy

• STIs

 If you observe spotting after sex, or on any day other than your period or ovulation, see your ob-gyn to find out the cause.

Sources:

The differences between spotting and periods, medicalnewstoday.com

Why Am I Spotting Between Periods? webmd.com

Menstrual Bleeding Patterns Among Regularly Menstruating Women, ncbi.nlm.nih.gov