I am 21 weeks pregnant with my first child and i have been put on this 2200 calorie diabetic diet for high blood sugar during my glucose intolerant test. i have been following it very strictly but everytime i check my blood sugar level it is low...like 75 one time and another 79. is this normal? should i call my doctor? what should i do?

That seems pretty low. You should definitely call the doc and talk to a dietician.