“Still have the occasional breakout while on accutane”

I've had moderate acne problems since i was a teenager. I tried everything under the sun including laser treatments but finally decided to take Accutane as a last result. I have been taking it for 2 1/2 months gradually increasing my dose from 10 mg per day to 40 mg per day. I haven't really had many side effects except for dry skin.

Is it normal to still have the occasional breakout when I have been on Accutane for 2 1/2 months? It happened once but I believe it happened because I was approaching my menstrual cycle. I'm just wondering whether this means that the drug isn't working. Most of the time though, my skin is clear.