What causes light bleeding before a period?

Light bleeding before a period can occur for a number of reasons, such as ovulation, hormone imbalances and medications a women is taking, according to WebMD. Many women experience light bleeding between periods, and alone, it is little cause for concern.

Starting new birth control pills or taking the pills at different times each day can also initiate spotting, according to WebMD. Having an IUD can increase a woman's risk of light spotting throughout her cycle as well. In very rare cases, abnormal bleeding between periods can signify a more serious medical condition, making it important to seek treatment if abnormal bleeding continues.