Does Missing Doses Of Accutane Cause Oiliness And Blackheads?

I am currently on accutane. I am in my 4th month and my doctor just increased my dose from 40mg a day to 60 mg a day. However, my face has become extremely oily, when for the past 2 months it had been extremely dry and I have have a ton of blackheads. I counted my missed doses and realized I had missed at least 3 weeks worth in the past month and a half. Is the oiliness and blackheads normal in such a situation?