Although Keflex is a wide spectrum antibiotic, only your doctor can determine if it would work or not for the infections you have. Yes, it is distributed everywhere ( with a few exceptions) but it may or may not be effective. If you have an urinary tract infection you need an urine culture, for a cut you may need atetanus shot not antibiotics. If there are signs of infection, like swelling and pus, you need a culture, Keflex may not work. For an ear infection it may or not work. So ask your doctor. Don't auto medicatte, it could be dangerous, you don't know for how long, you don't know if the bacteria are sensitive to it, you don't even know if you need it.
If, on the other hand, your doctor prescribed them, then take them, he must have good reason to give you that abx.