Hey..72 hour mark is usually where most people feel the worst of the wds, but that's not an exact scientifically proven fact, lol! Some people feel the worst on day 3, 4, 5, or longer...some feel the worst on days 1 and 2..I hope you weren't totally counting on that :) It's just a protocol of sorts, what the average is.
So day 4, congrats on that! Every day here on out you will feel a little better than the day before.