Bright Red Blood
This usually indicates the very start of your cycle, and the shedding of your uterine lining. In very rare cases bright red blood could indicate a ruptured ovarian cyst or miscarriage. (Other symptoms of a ruptured ovarian cyst - which is more common among women with polycystic ovarian syndrome - are sharp pain, dizziness and weakness.)
Dark Red Blood
This just means your blood has been around for longer. This colour blood appears at the end of your cycle due to high estrogen levels, thick lining and a slower shedding rate (all completely normal).
Brown or Black Blood
This is most common at the very end of your period (light flow or spotting), as the blood has been stored up the longest.
Light red or pink spotting immediately before your period begins can indicate low estrogen levels. If this persists, head to your GP as hormonal issues can lead to other problems later in life (infrequent periods and dryness to name a few).
If there is an orange tinge to your blood check and there is a bad smell, this could be a sign that your blood has mixed with cervical fluids, which is usually an indicator of an infection or STD. See your GP.
This is actually pretty common, especially towards the end of your cycle. But if there’s an unusually high amount of clotting, this can signify a miscarriage. Contact your doctor if you’re worried.
This article originally appeared on Women's Health.