Is it ok to cut a day out of my training plan?

I just got back into running a few weeks ago after suffering from a knee injury, and my training plan started with three days and this week it bumped up to four. I've noticed an astronomical difference in how much this fourth run is becoming a burden on my life. Maybe I'm just having a rough week, but I just feel like with my busy schedule it's another stress on my life and running is something that I usually use to help me relax. I guess I'm asking if it's ok to keep increasing the mileage each week if I'm only running three days instead of four like the plan recommends?