Will my boil form a head, or should I go back to the clinic?

I've had a boil on my eyebrow for the past 11 days. It started out the size of a dime, and is now the size of a golf ball. I went to the clinic 2 days ago, and they gave me antibiotics and the doctor said that he couldn't see it getting much bigger. However, 2 days ago it was only the size of a quarter. Since then, it has swollen to the point where I can't open my right eye very much. It hasn't formed a head yet, but it has been softer in the center for about 3 days now. The doctor said he couldn't lance it because it wasn't ready 2 days ago, and it was dangerous because it's close to my eye. He said if the antibiotics don't help, he will refer me to a plastic surgeon to do it so the scar isn't bad. But I don't know how much more I can take. It gets bigger everyday. Will it form a head soon, or should I go in and demand it be lanced?