It depends on whether the day is in-hospital or not. OB/Gyns usually divide their time between office visits and hospital work.
During an office visit day, you may be doing pre-natal checks, sonograms, or pap smears. For in-hospital days, you may be delivering babies, sometimes requiring Cesarean sections. The average for an OB/Gyn is about 12-15 deliveries per month, but this can vary greatly.
The schedule can be very hectic, because you're on call for deliveries which can happen any time of the day or night, or weekends.
Take a look at this video, which talks a bit more about the day-to-day of an OB/Gyn, as well as skills required: