It can, depends on when you when you took the test and if you have eaten anything. Usually, when I test, if it is high and wait about ten minutes before testing again. Especially if I test first thing in the morning before eating.
two reasons for the difference:-
1. you are rising or dropping quickly. You would assess this depending on when you took meds, their impact, when you last ate.
2. The meter is not 100% accurate. There is actually a permissible amount of variation. Some meters are better than others. Sometimes meters will be more accurate closer to the normal range of blood sugars (70 - 140 or so) and less accurate with much higher numbers.