Got prescribed percocets for hysterectomy. I have been taking for a month straight. I am not out..Withdrawals?

I have been taking 3-4 percocets a day for about a month, some days less though. I had a hysterectomy and got them prescribed. Well, I'm out. Am I going to have withdrawals? What can I expect? When will it start? I'm really nervous and scared. I'm kinda grouchy today, is this why?