Medium Lumps On Skull

I have had a medium lump on the left side of forehead at hairline for 5 years. Doctor took xrays and said it was bone and sometime bones just grow like that. It seemed bigger so I went to another doctor a year ago and he took and xray and said it was fine. It is only noticable if you are looking for it because my hairline shape hides it. I had my hair colored last week and the stylist said I had a few "bumps" on my head. I shrugged it off but I noticed 2 bumps at the back of my skull about the size of quarters that were sore this week. I have now noticed another one today behind my right ear about the size of a dime. They are hard, like bone but are sore and are starting to cause me headaches. Whether this is because of the bumps or because of the stress that I am scared I don't know. I know I need to go back to the doctor, but I do not have insurance coverage until August 1st. Could this be something serious or could it wait?