Hi,
Wait for your results. Let us know. We can't predict these things. It may or may not have risen.
Good thing is that you are still young and that means if you take care of yourself now things should be fine.
Diabetes management is a marathon, not a sprint, so you need to be focused on managing this for the long term.
Yes Aic can go up 3% in6 month. The A1c is an average So yes if your average goes up so does the A1c.
Do not look at it as percentages. Look at the points. An A1C is going to be different every time. There is no normal as far as how much it changes. The idea is to get it below 6 and keep it there. Exercise, even walking, will go a long way toward keeping it lower. The body uses glucose in the blood for fuel before it uses other sources, such as insulin, to control the glucose. Try to watch your carbohydrate intake. 1 mg sugar = 1 mg of carbohydrate. Of course watch your sugar intake. Regular soda and sweet tea should not be part of drink selection. Alcohol should also be avoided. Though an occasional drink is OK.
You can find a lot of info on diets for diabetics and pre-diabetics online. There is no need to have a special meal just for you if you can manage portion control. A slice of cake or another sweet treat, one or twice a week, will not hurt you if you manage your carb/sugar intake.
Good luck.