I don't know what to do!

I was in a wreck today where I was hit from behind. I felt ok but now I am having intense pain in my lower back. I had read that was not good and you should contact your doctor. I just don't want to be one of those people that go to the dr for no reason after a wreck because I did feel ok when I left the scene. I am only 6 weeks so could it even affect the baby this early? If it doesn't then atleast I feel better and know that it is just from the wreck and should go away in a couple of days....