I have the same issue. It happens very frequently in depressed or mixed episodes but it happens at least once a day no matter what mood state I'm in. Like today just a few minutes ago I had one and I'm having a good day. I feel like for me it's almost like an addiction. I've been self harming for so long it's just a part of me and it probably will be for the rest of my life. I try not to let the random ones bother me. I just accept it ( if you fight it it gets stronger) and move on. If I'm not in an episode they don't haunt me and are not dangerous. Just annoying.