what the hell!?!?!

i got diagnosed with GD when i was 28 weeks. im now 36. i have eaten the exact same thing every day for breakfast and lunch since getting GD. my sugars have been great except for the last 4 days. today for lunch i had my salad and my string cheese and i was super busy at work and for sure got in my 20 minutes of exercise plus some, amd my sugars were at 152 when i took it 2 hours after eating. this morning after breakfast it was 142 after my exercises amd everything. im just so confused and very frustrated! anyone have this happen and what happened?