4 days is not enough time for anything to happen really. You'll be fine.

I've just finished my 6th month on accutane, very low dose as well (20mg/day) and although I've gotten a little bit oilier, my skin is still clear. Its been about 3 weeks since my dermatologist recommended I take a break, but I will be back in 2 weeks time.

So no, don't worry, nothing is gonna happen and you won't lose any progress.