Hesitating to take antibiotics

40, M, 5'8", 170 pounds. not on any regular medication, never smoked, drink occasionally.

I had a cut on my hand and my doctor had found a splinter in there. They want to start me on antibiotics (500mg of Cephalexin) 3x a day for 7 days.

while I understand you should always listen to your doctor, I am sort of hesitating just because I know the havoc antibiotics could cause on your gut. Do you guys think I should wait and see? Then take it first sign of infection? Or if I take a probiotic a few hours apart, would that kind of even everything out?