It really depends. I overplucked mine, but they are slowing growing back, but it is noticeable. Two weeks after plucking you'll already be noticing some hair growth hopefully, especially if it's your first pluck. But be very careful since overplucking many times may cause damage to the follicle and hair that used to come from them will never come again.
It may take awhile, but they will surely grow back. I know it's very hard to resist the temptation but leave them alone for some time and do not touch the tweezers (only to remove stray hairs) and your eyebrows will come to the natural shape.
