Ever since the beginning of time, women have had to learn to coexist with our monthly periods. Sometimes that coexistence isn't always peaceful. But how do we know which aches and pains are normal and which ones are justification for a visit to the doctor?

To truly answer what's normal and what's not, you have to be in tune with your body and know how it typically responds to the monthly hormonal changes.

Many women develop PMS, or premenstrual syndrome before their period. Because of the fluctuating hormone levels, it's normal during this time to experience a gamut of strange body changes including tiredness, pimples, backaches, cramping, irritability, headaches, sore breasts and bloating.

Even though these symptoms are generally associated with PMS, if they are not symptoms you typically experience and they suddenly appear or begin to cause you problems, it may be time to seek a medical opinion. Don't be afraid to turn to your doctor for help.

Here are some examples of period problems that may signal it's time to make an appointment with your doctor.

Cramping
Many women complain of cramping, which is caused by the uterus contracting. While cramping is normal for many women, what is not normal are cramps have you doubled over in pain or that are so debilitating that they cause you to be unable to participate in your normal daily activities.

Heavy Bleeding
Again, this depends on the woman. Some women naturally have a heavy blood flow each month. However, if you suddenly see a drastic change in the volume of blood during your period it may signal a problem. If you find yourself filling up a pad an hour with heavy blood flow, you may have a condition called menorrhagia. Menorrhagia is usually marked by heavy periods that last a long time.

Irregular or no periods
Stress can always wreck havoc on our bodies and sometimes cause our period to get off schedule. However, if your periods have been like clockwork and you suddenly stop having them or begin having them sporadically, you may need to see your doctor. This could be an indication of a hormone imbalance problem or an indicator of improper eating habits.

Strange discharge or smell
If your smell is suddenly altered beyond what is normal for this time of the month and has become a foul smelling discharge, you may have infection of some sort.

Unusually painful headaches
If the headache only appears around the time of your period and is blinding or again, is so painful it that it disrupts your daily life, see a doctor. Hormonal imbalance may be the blame.