Back Pain Has Begun....

It started yesterday & I know that I really shouldn't complain since I really have had an awesome pregnancy but couldn't it have stayed that way? Why spoil me with no "side effects" if all of a sudden you are going to hit me with a mac truck. Yesterday my lower back started to feel sore & ache while I was at work but then when I got home seemed to get a bit better until I tried to sit down on the sofa & relax at about 8......I guess I dozed off because Lance woke me up at 11 to go to bed (I don't even know what time he got home from work) & when I tried to get up off the sofa my back pain was HORRIFIC to say the least & it has not let up all day.....WHY did this have to start?? Why couldn't I just continue to have my wonderfully pain free pregnancy??