Why do my period last for 9 or 5 days. Mostly 9 is something wrong it's been this way for a year now I'm 20 years old and trying to have a baby?

Cycle control . Any obgyn can give you treatments to shorten or lighten your periods. Most treatments will also prevent pregnancy. You will have to decide which is more important at the young age of 20--- getting pregnant now or controlling long cycles.