I think the important question to ask and be honest with yourself, is how does it make you feel, or how will it make you feel, finding something you don't like? Example, seeing a picture of your ex with somebody else, or seeing your ex looking happy without you. You can misinterpret both those situations, think the pic with sombody else is somebody your ex is interested in or seeing him happy may make you think he has moved on. The thing with social media is that it's just a small sliver into a person's life, and only allows you to see what the person wants you to see, and in the they want you to see it, creating an illusion of their life. This can be a really unhealthy habit if it doesn't make you feel good. And it may not allow you to accept the situation and move on with your life. Think about slowly reducing the number of times you check, busy yourself, make it hard for you to access your ex's social media, or go cold turkey and block and delete. It will be hard but worth it, and will make you feel better in the long run. Good luck!