I Have Been Prescribed Prednisone 20 Mg, With The Direction

I have been prescribed prednisone 20 mg, with the direction of taking 1 tablet three times daily for 3 days, then 1 times 2 for 3 days, then 2 tablet for 3 days, (totalling 18 tablets) for spasm in my neck 4 weeks after laminoscopy. I have followed these directions for 2 1/2 days (using 7 pills so far) and suddenly noticed I had only 4 pills left in the bottle. No refills. What should I do? The spasm in my neck is getting better meanwhile, but still need to lie down and rest my neck to make the pain go away.