Does appendicitis pain come on gradually or all of a sudden?

For the past two days, I have had sharp intermittent pains in my lower-right abdomen. I know pretty much nothing about appendicitis and am wondering if I might just be in an early stage (where it hasn't actually ruptured yet). To those of you who have had it, did it come on gradually or just appear all of a sudden? If it was a gradual thing, how long before you realized it was time to see a doctor? Thanks in advance.