With the first time I was allowed to eat and this time he said fast for 12 and have to do for 2 hours. I can't imagine doing the 4 hours
I had this happen with my first pregnancy. They are serious about not eating anything and I did eat a little something hours before the test. So, do complete fasting if you didn't. I took the shorter test and failed and then had to do the 4 hour test. Came back normal/ no problems. Try not to worry. good luck