Spotting is any bleeding from the vagina that is not due to a woman's monthly period. It is usually light and lasts for a short period of time. Spotting can be caused by a variety of factors, including ovulation, hormonal changes, pregnancy, birth control, infections, and other health conditions. The main difference between spotting and a period is the quantity of blood. Period blood, even when light, is usually more consistent and lasts several days. Spotting does not usually point to a serious medical issue, but it is always a good idea to have your doctor check out any unexpected vaginal bleeding, especially if you’re not sure of the cause.