Brown discharge does not automatically indicate pregnancy, but if it occurs slightly before a regular menstrual cycle and there is a possibility of pregnancy, a pregnancy test should be taken, according to What to Expect. A brown discharge, called implantation bleeding, is a common occurrence 10 to 14 days after ovulation when the fertilized egg attaches to the uterine lining.
If the brown discharge is caused by implantation bleeding, it is typically much shorter and lighter than a regular menstrual period, according to What to Expect. Implantation bleeding can be accompanied by light cramping. The blood is generally either brown or light red, and does not contain any clots. If a pregnancy test is negative and the woman is taking birth control pills, breakthrough bleeding can cause brown bleeding similar to implantation bleeding as the body adjusts to the hormones in the pills.
According to Healthline, in very rare cases, brown bleeding can signify an advanced stage of cervical cancer. Getting a regular pelvic exam and Pap smear helps to prevent undiagnosed cervical cancer from advancing to this stage.
Women with unexplained brown spotting should contact a doctor. While most causes of brown spotting do not indicate a serious problem, it is important to deal with health concerns promptly in the case of a larger problem.