As always, you should direct any questions to your doctor or pharmacist. If you questioned the dosage, i.e., were given different instructions from your doctor, that would have been the ideal time to bring it to their attention. You can also call the pharmacy that filled the script and ask the pharmacist about it.
CEPHALEXIN is a cephalosporin antibiotic. It is used to treat certain kinds of bacterial infections It will not work for colds, flu, or other viral infections.
Don't rely on strangers on the Internet to give you sound, medical advice - we don't know your medical history.