I agree with KB.
First make sure that nothing really emergency happened, something that does not allow your supervisor to respond and then you can take the issue further.
I sould also say that I understand how you are feeling. Although now I have 2 very good supervisors, who give me feedback in a week after sending them my work, I wasn't so lucky during my MBA. I had a tutor/supervisor who was taking 3 or even 4 months to give me feedback! the worse thing was that that time was time that extended my course and meant that I had to do it in 3 years instead of 2! And the reason he gave for the longest dealy, was that he was on holiday for 3 months and he didn't want to have anything to do with work!
Anyway, good luck!