I brushed my teeth hard a couple of time and got a white line in my gum line. have i receded my gum?

See a dentist: Receding gums isn't a good sign and can't repair themselves. It is not only cosmetic problem; they can lead to tooth decay, tooth loss and/or gum disease. Unfortunately, there is no cure for receding gums, but there are some preventive and simple steps: soft brushing, reduce plaque buildup, night guard and most important visit your dentist 2X a year. Take care.

Brushing hard: Brushing hard can damage the sort tissues in your mouth and can cause gum recession. Better to brush thoroughly but gently w soft t'brush. White line is not enough information. On the teeth, the gums, location, duration, size, etc. Please see your Dentist for thorough examination, professional cleaning, pathology evaluation, and appropriate individualized oral hygiene program.