I have a red spot on the soft part in the back of mouth. i have been experiencing neck and shoulder pain on that side of body previous to that spot ap?

Probably nor related: Probably not related but check with your dentist to evaluate the soft palate for a diagnosis

Could be viral: Your symptoms could be those of a viral infection. The redish area in your throat is classic, as are the myalgias in your neck and shoulder. However, if those symptoms last more than 7-10 days, then something else is going on and you should see your PCP.