Yes, It's somewhat inaccurately called the "purge".
TLDR the cells lining the inside of your pores are constantly turning over. This process tends to malfunction in people with acne, and isotretinoin "resets" the cell's "programming" on a genetic level so it works correctly and you aren't so acne prone in the future. During the transition, the turnover completely stops, but sebum (oil) production continues, causing a backup within the pores that results in a flare up of bacterial growth.
It's temporary, brief, and only occurs once in each area it affects. Once it happens and clears up, expect to see it occur somewhere else next.
It's a good sign the accutane is working. I had it occur in place I never got acne before, like my stomach.