How many days worth of antibiotics have u been given? Usually it's three for kidney/ UTI prob your delivery won't be with you for a good few days anyway. As long as ur finished your course by the time you start you will be ok... Only for the fact the enteric coating on tabs would prob stop you from getting into ketosis, no other reason... Actually the high water intake on this diet would be good for you. X
If its not the sort of antibiotics that you have to take with food you should be okay. I had to take some before and it didnt affect my diet at all. If you have to eat then could still start and have some chicken each time you take a tablet ..just a thought. I hope you get better soon though, its not fun being sick.