Why does my pinky knuckle pop everytime I bend it?

Hi for about a year now, my pinkys been being weird, and every time I bend my finger about half way, it makes this popping sound, and you can see the knuckle pop out of place, and I can feel it, and if other people see/feel it when they are touching my hand, and it creeps them out. Sometimes, it's even worse than it normally is and my finger will suddenly shoot back when I bend it. It doesn't pop when I straighten it, but it's uncomfortable. It never hurt before, but now it's been hurting horribly, and it's been causing me problems with my daily life. I dint recall any injury or accident that happened before it started, and it definately was never broken. It's my right pinky, I'm right handed, and it's causing me problems. Also, don't tell me that it's just cracking, because when bones crack, they don't pop out of place, or hurt, or make such a strange popping sound, mire if a cracking sound. Please tell me what is wrong with my finger? I googled it but I couldnt find anything similar. I plan on going to the doctor when I get back from vacation. Thanks in advance!