What am I gonna do about my dislocating knee cap?

About 8 years ago, I dislocated my knee cap. It happened for like no reason at all. I stopped to stretch and it popped out. It was the most painful thing I had ever experienced. When I straightened my leg, it popped back into place. I thought it was gonna be ok because it didn't really hurt but it popped out a couple more times that evening. The next day it really hurt and my leg was huge. My mother claimed she had the same problem with her knee once and that it was hereditary so, she didn't take me to the hospital. After a month it was normal. It wasn't until about 4 years later, after I had my son, that it popped out again for no reason. I was leaning over to set my baby down and luckily was able to before falling to the floor to cry. On occasion, it slips and pops when I step but usually only lasts for a little while. For the past 3 days it has been doing it often and it is more painful than usual. My question is: Is it possible to permanently dislocate your knee?