The signs of menstruation can be used to determine your fertility

Menstruation is one of the best methods to reflect your fertility. The details of your menstruation can act as a window into your fertility, telling you what is going on, how your reproductive circulation is, if the hormonal level is imbalanced, etc./

Missing a period
There is no need for alarm if you only miss one period. The hormonal balance is very delicate and it can be easily affected by many reasons such as stress. And in general, it will reset itself. Missing one or a couple of periods does not necessarily means you are infertile as long as you can still ovulate .

Having short menstrual cycle
Short cycles can cause fertility issues due to lack of ovulation, too short of follicular phase or luteal phase, lack of nutrition, deficiencies, anemia or low body weight. Traditionally one of the best herbs that has been used for luteal phase defect is vitex. In studies vitex helped 83% of women experiencing luteal phase defect.

Have prolonged periods
A longer period may be an indication of hormonal imbalance and/or a failure to ovulate. Progesterone secreted by the body after ovulation normally helps to stop excess bleeding because of its effect on preserving the uterine lining. If estrogen is high or progesterone low, bleeding may continue longer than usual. Some herbal therapies that have been traditionally used for balancing longer periods are vitex and Slow Flow.

Heavy menstruation
This is known to be caused by prostaglandin imbalance and/or over-stimulation of the uterine lining from estrogens (estrogen dominance). Common causes of this condition can be seen in the following website:
http://www.drleetcmclinic.com/Symptoms_Checker/61.html

Light menstruation with strong cramping
Generally the cramping could be helped by using herbs that have an anti-spasmodic, calming effect on the uterus. If there is light, bright red menstruation, this may also be a sign of a lack of circulation to the uterus (called “a cold uterus” in Traditional Chinese Medicine).

Bright Red Blood
Generally bright red blood indicates a healthy period.

Dark, brown or thick blood
Thick dark blood that looks old or brown is old blood left over from the previous cycle. This may be caused by a sluggish menstrual flow, lack of uterine tone or low uterine circulation.

Pale Blood, Watery or thin menstruation
Pale pink, thin blood traditionally signifies poor blood quality which can be enriched by using blood building herbs, hormone balancing, and increasing circulation. Eating a healthy diet may also be beneficial.

Spotting and bleeding between periods
Spotting is a tough to eradicate as it can be caused by many different factors. In most cases, it is not something to be concerned about. However, there are some exceptions:
Failure to ovulate
Endometriosis
Abnormalities of the cervix
Ovarian cysts
Hormonal contraceptives
Excessive exercise
Poor nutrition

Amenorrhea
When you are trying to get pregnant, it will be quite frustrating if you have amenorrhea. Having a healthy cycle is step one for boosting your fertility naturally and being able to get pregnant. There are a couple of reasons your cycle may be irregular in women in their reproductive years such as stress, dietary deficiencies, low body weight, getting off of birth control pills, hormonal imbalance, menopause, or other underlying health issues.