Is any one here a vet or know a lot about dogs? Got some quick questions?

Ok, my dog's almost got into a fight Tuesday evening. I was there so it didn't get very bad. But one did manage to bite the other. It isn't vey bad, just a small laceration on her chin/neck area. I noticed it yesterday and I flushed it and cleaned it good with Nolvasan. It doesn't look infected yet. I've got cephalexin(infection pills) that was leftover from the multiple trips to the vet for different reasons. Last time we had a dog fight all the vet did was clean the wound and give infection pills. So my question is can I give her these pills to prevent infection? I don't see paying all that to get the same thing I have. I'm going to call my vet when they open but I was just wondering if that sounds ok. I know the dosage and the instuctions on what to do. So do you think thats ok?