You took an i pill on 12 November. That was 20 days after your last period. Since you don't have regular periods so it is difficult to say whether that was a fertile window or not.
If you had conceived on 12 November then your urine
pregnancy test will be positive by 3 December, irrespective of the irregularity of your cycle.
I suggest you should get
beta HCG level done on 3 December. If it is negative for pregnancy then you can consult a Gynaecologist for treatment for withdrawal bleeding.