You might have a hormone problem. Lots of women have a very long period but your doctor is the only one who can tell you why. Sometimes birth control pills are given to straighten out this problem.
Many women have long periods and it may be normal for you. If this is a change for you, you might want to visit your doctor. Some women have periods as long as two weeks!
Not necessarily but it's always best to get things checked out if this is not a normal occurance for you. Peoples periods last different amounts of times and there are so many things that can affects them.
I've heard some people have long menstruation, and it's normal. Depends on how long their ovulation cycle is. It is wrong when u have short cycles (e.g 28 days) but long periods, maybe you should check your hormones.
Ten days is pretty typical for a healthy period. It can range from 3 to 10 days. By getting on some sort of birth control like the pill, you may be able to lighten it up a bit.