Someone bit my lip and drew blood. its swollen and very red. do i need to go see a doctor for any antibiotics/how high is the risk of infection?

When was the bite?: If it was today or yesterday, it may just be the acute reaction to the physical trauma. However, if it is extremely painful and/or getting worse and the redness is spreading with or without accompanying fever, it may be infected. If so, have it checked out by your doctor. The mouth has a lot of bacteria so the risk is a bit higher but not a common reaction. Ice may help. Good luck!

Fever?: If you have an elevated temperature and/or see infection, you should be seen immediately. Else the swelling is likely due to trauma of a highly vascularized tissue and application of ice and an anti-inflammatory should be all you need to resolve the swelling.

See an oral surgeon: Trauma to the lips is quite common. The lips are very sensitive to trauma and swell up quickly and ugly. It is particularly important to have an experienced surgeon stitch cuts that cross the vermilion border. See an oral surgeon for evaluation and treatment if needed.

See Oral Surgeon: See the Oral Surgeon to be sure you do not need stitches and/or antibiotics. You may apply ice to the area to help reduce the swelling (20 mins on / off) for a few hours for the first 48 hours if possible. Also take ibuprofen to help with the soreness and inflammation. May need only time to resolve, but best to be sure. Follow the above. Good Luck.