Parkinson disease is a progressive disorder of the nervous system. The disorder affects several regions of the brain, especially an area called the substantia nigra that controls balance and movement. Often the first symptom of Parkinson disease is trembling or shaking (tremor) of a limb, especially when the body is at rest. Typically, the tremor begins on one side of the body, usually in one hand. Tremors can also affect the arms, legs, feet, and face.
It might be heavy but short. It might only be spotting. A short period might mean you're pregnant. These can all be signs of a pregnancy. The only way to sort out the pregnancy from the rest of the reasons would be to take a pregnancy test. Sometimes what a woman mistakes for her period is really what we call implantation bleeding, a slight bleeding that occurs and the baby implants into your uterus.
From the point of first menstruation, a girl's periods will likely be irregular for several years. Even when the menstrual cycle is regular, girls may have cycles as short as 15 days or as long as 40 days. The amount of her menstrual discharge may also vary from month to month, but on average a girl will lose about a quarter-cup of blood during her period.