My 13 year old daughter has been having a shooting pain on the top right of her head?

My 13 year old daughter has been having a shooting pain on the top right of her head since last march or april. The spot was probably about a inch big. When we first noticed it there was a bump but it went away within a month so we didnt worry about it until a few months later. The doctor had us follow up to take her for a MRI but they did not find anything so we left it alone and a few weeks to a month later, the dot extended to about three inches and goes to the back right of her head. We do not know rather to follow up with the doctor again or leave it alone because they did not find anything in the MRI . Is there any other tests they could do? What could it be?