Blood sugar

I failed my blood sugar test recently and my gynae wants me to control my diet till I deliver. Today is my 2nd day of switching to a low gi diet ie brown rice, wholewheat, bran etc. I tested my own blood sugar 2h after each meal breakfast lunch and dinner. The normal range should be anywhere between 5 to 7 mmol/l. My breakfast and lunch results were 5.3 and 6.3 respectively but dinner spiked up to 7.9. Am a little bummed by this. Any one having the same issue? Is it ok for the night result to be higher?