How long does it take to recover from whiplash?

I got into a car accident on October 2nd. I had whiplash and I was taken to the hospital to check for any problems. They didn’t find anything but said I should be sore for a week or so.

It’s been almost a month and I still have shoulder and neck pain when I move my shoulder up. The weird thing is, my left neck and shoulder has pain when the accident was on my RIGHT side. My right side of my body doesn’t hurt but it seems to have affected my left side (shoulder/neck).

I don’t think the doctor can do anything else besides give me some muscle relaxers since it’s more of a tissue problem than bone problem. My boyfriend still has problems with his neck too.