I agree that the pills are so small that the amount of sugar they contain is unlikely to affect your blood sugar; however, if you really need a strict accounting, I think the suggestion to weigh them would work as long as you make sure you're looking at carb count by weight and not by volume. Otherwise, crush them and use the volume to estimate carb count.
I have used both arnica gel topically and arnica pills (typically called pellets) for some time now and have found both products to be very helpful for treating bruising and sore muscles.
Good luck with your surgery and recovery.