There are several causes of an early period. It could be stress, changes in your lifestyles, or a hormonal imbalance triggering menorrhagia along with irregular cycles. Although the average cycle is 28 days, it is perfectly normal to have a cycle that is as short as 21 days or as long as 35 days. You do not state your age. If you are a teen or a woman in her 40's, you may have a cycle that change a lot due to hormone imbalance problems. On the other hand, an early period could be a sign of early pregnancy (i.e., implantation
bleeding) or a miscarriage.
Generally speaking, abnormal uterine bleeding that may indicate a miscarriage is different from normal menstrual periods in which bleeding that not only continues but increases in amount and frequency and that might have more clots; the clots would look like tiny lumps in the vaginal discharge. You may also experience mild-to-severe lower back pain or abdominal pain or cramping, either constant or intermittent, a gush of clear or pink fluid that passes from the vagina. Despite what most people think, it is not always easy to tell whether or not you have had a miscarriage. Some wonder whether abnormal and irregular periods might be very early miscarriages. And for those who know they are pregnant, miscarriage symptoms can be hard to interpret because signs may not always be present and common symptoms do not always mean a miscarriage. Only a doctor
can tell you for sure after a pelvic exam and a serial hCG blood tests or an ultrasound
. I recommend you consult an obstetrician soon.