Why do i have stretch marks, if i've never been over weight or had any kids. is there something wrong with my body.?

Nothing wrong: You can get stretch marks from your growth spurt during puberty. Some people are more prone to stretch marks than others. There is nothing wrong with your body, it just happens sometimes.

Stretch marks are…: Often associated with pregnancy or obesity, neither of which is your problem. They occur due to the rapid growth of the abdomen. Body builders also experience them when their muscles grow rapidly. A medical condition, cushing's disease, may have stretch marks, but it is also associated with unusual weight gain. If you exercise often, the rapid increase in muscle size can bring stretch marks.