Is Irregular Menstrual Cycle Normal After Norethisterone Use?

I had a normal/heavier period 4 days after stopping the Norethisterone (I used it to delay a period), how long until my cycle is normal again? I am on day 32 since the other one started and have not gotten another period. I have not had sex at all? Is it normal for the cycle to be irregular after using this medication? I am typically a 26-31 day cycle. Thanks