5. Dark brown
Dark brown or dark red may mean that some of the old blood has been “sitting” inside your uterus for too long. Nobody knows why this happens, but this is considered to be a normal thing.
Watery, almost without color or super-light-pink menstrual blood means you are either nutrient-deficient, or you could even have ovarian cancer. But don’t get too nervous, fallopian-tube cancer accounts for less than 2 percent of all gynecological cancers.
7. Pink-ish color
Pink-ish colored period blood may signify low estrogen levels. If you’re an avid runner, this could also be a reason for your menstrual blood to be light in color, as it’s been proven that playing sports, especially running, may cause the estrogen levels to drop.
It’s something to watch out for as some studies have found a connection between low estrogen and osteoporosis later in life.