You may have delayed some very important medical treatment if you have not gone on the day of the collision. It's just critically important, even if you think you're not hurting that bad because the next morning is when you're likely going to be hurting the most. All of my clients come in and they'll tell me, “You know, I didn't really start feeling bad until the next day or they're the second day”. So when I get a call from a potential client asking me what they should do, I always recommend that they should get checked out by the emergency room.
You're going to get x-rays, you're going to get basic medical care, basic check ups that's very important for later diagnosis. Also important, is that there is a record of your injury that's made by the hospital. You'll be surprised at how the insurance companies will try to say, well, they didn't go to the doctor, to the hospital for two or three days. Therefore, they must have been injured somewhere else, so it's very important that you seek immediate medical treatment, even if you're not hurting that bad, because more likely than not, you're going to be hurting worse the next day.