Asking a Professor to sign me to a group I have a class assignment coming up. On the syllabus, it was indicated that groups would be assigned this week. I assumed that the professor would be assigning groups. However, last week the professor said that we need to choose the people we work with and come to him afterwards. I don't know anyone in my class and have a class directly after and before. I asked a few people and they had already chosen their friends to work with. 

I sent him a polite email last weekend, asking him If he knew of anyone looking for an extra group member since I've been having a difficult time finding a group. It's now Monday night and he still hasn't answered. I'm panicking now since groups are due tomorrow and I have no form of contact with anyone in my class to even try and form a group. What do I do?!
Send another email stating that you have been unable to find anyone and have been refused by a few teams. You will try to "catch" him before class.

Then (choose one) if you don't get a suitable reply:

(a) Show up at his office in the morning before class and present the problem. Ask for a solution. I.e. "How should I proceed?"

(b) Catch the prof in the hall just before class and ask for a solution.

(c) When class is about to begin, raise your hand and ask for a solution.

(d) After class catch the prof and ask for a solution. 

There isn't really much else you can do. Prefer a to b to c to d, I think. But, I assume the prof has seen this before. You might not be the only one with the problem so a group might be formed immediately.