Hi, honey. The early period cramping is very common. It is caused by the prostaglandins that make your uterus contract to shed the period. Imagine your uterus like a fist, and it is squeezing tightly and not letting go, the blood can't get back into the muscle for a minute. The muscles call out with pain to say they need the blood to come back. Then the cramp releases and the blood flows back into the muscle, and all is fine for a few minutes and then it happens again. That's what is happening, your prostaglandins are working. Antiprostaglandin medicines are readily available, Advil and Nuprin (in other words, ibuprophen) are antiprostaglandins. They relieve the cramping very well.
5 days is the most common length for a period. But even if it were not, it might be normal for you. The key is to watch what your body does, and set up your own calendar so you know what normal is for you. One easy way to do that is to use graph paper turned sideways, and list 1 through 30 across the top (as headings). Then put the day you start your period (i.e., 7/14) in red in the "1" column, and the next day (7/15) in the "2" column, and so on. Change the color of the date once your flow ends (like, go from writing the date in red to writing it in pencil). Use some kind of symbol like an asterisk or triangle for any day you notice clear, copious mucus, and another symbol (like a little lightning bolt) for any day you have cramps. At the end of the month, start a new line with the date of the new first day of your next period. By the time three months have gone by, you will have a great chart that tells you: how long your cycles ordinarily are, how long your period usually is during that time, when you might ovulate, when you usually have cramping, and (because it gives you historic data on when your periods come) when your periods might come in the next few months. This is handy for planning, since you don't want to be caught somewhere without your "female supplies" on a day when your period is due.
The black stuff coming out of the vagina as a period is ending is the last of the endometrium (period blood). The saying is "brown blood is old blood." Nothing to worry about.
well you can take aleve that always seem to help me and most periods last 4 to 7 days sometimes longer. As far as the black stuff that comes out im pretty sure its not black and just a dark brown but thats normal as well its just old blood coming out of your body.