1st time alone in the House in 3years

DAD HERE. My son has been home with me since birth. I work from home and he's been here with me every day, until Today. He started aba school. I thought I would feel sad because I have a huge attachment to him and he only responds well to me in every aspect of his life, but I actually feel okay and am enjoying being home alone, especially since it's my day off from work as well. I'm kinda mad that I'm not missing him more. I dont really remember what I like to do when I'm home alone. Kinds feel lost. Does it get better?