Is my workout routine intense enough?

First of all i have a fast metabolism. I ve been working out for months and haven t gained weight. I just need to eat more i know. I ve gotten leaner and muscular but still small. Also i only workout at home.. I work out four times a week. Monday i would do about 45 pull ups half of them are weighted with 10-15lbs. 3 sets of 20 decline pushups military style baby. 3 sets 15 rep squat with only 30lbs. I also lean against the wall for 2 min for leg workout. Wednesday I would do 45 chin ups half of them weighted with 10-15lbs. 3 sets of 15 rep of hanging leg raises. then 3 sets of 15 rep ab roller exercises. Friday and Saturday are the same routine.