Why I Spent Most of My Day in Bed

I am more than bummed to share that I may be having a small setback with my training. I woke up with a pain in the lower left side of my back a few days ago. The pain does not bother me at all when I walk or run but it's there and I am thinking that continuing to running could make it worse.

I decided to make an appointment with my doctor to have it checked and he seems to think I have a lower back/lumbar muscle strain. He asked me to take a few days off from running, rest and ice the area. WHAT? I looked at him like he was crazy and asked him how many days is a few. He knows that I run and we always talk running when I see him. He used to run too so I am pretty sure he gets it when I look at him like he is nuts. I can only think of one way that this happened. Last Sunday I reached over the side of the four foot exercise pen, as seen below, that I keep the puppies in to grab something and I almost fell in. I guess I should have opened the door and entered the correct way! The pain dissipated and then a couple days later it was back and it was much worse.

I was planning my long run for tomorrow but it is on hold for now. I spent most of the day resting and icing my back in hopes that it will go away. The doctor gave me some anti-inflammatory pills but I am trying not to take them since they have a lot of side effects. I am hoping to be able to run on Sunday but if the pain is still there then I will go out of my mind and want to kill myself for missing my long run won't run. I really don't want to take a break but I know it is probably the best thing for me. It sucks that I may have an injury that was not brought on by running. I will take it one day at a time and see what happens. 

Have you ever had a lower back strain? Any advice?