Is Amoxycillin a good antibiotic to use as a preventative for infection?

I have a deep cut on the top of my foot that I should have gotten stitched and didn't. It's been a day and a half and it's still bleeding every once in awhile. I've soaked it in peroxide a few times and have it pulled closed with erfly bandages and put one of those new waterproof, advanced healing bandages on it. My roomie has Amoxycillin her dentist gave her just in case she got an infection when she got her tooth pulled. Since this is still hot and swollen, I was wondering if I should start to take it, just in case. I figure if the antibiotic reduces the swelling, maybe it will start to clot up a little and heal. If not, then I know I really have to bite the "no insurance" bullet and go get medical help. Wonderful healthcare we have here, isn't it?