This is why it is good to try to engage in other exercises too so that you can always do pushups in between the exercises. This will make it fun and also unbothered. You can also join a group of friends or neighbours who would also be a motivation. I had a neighbour some months back who was always engaging in exercise with me daily. He would always wake me up by jamming the dumbbells together outside my apartment early in the morning and that sound alone would always wake me and force me out. Other exercises like squats, jogging, gymnastics, stairs climbing and many leg works could be of help to solve boredom.