What should I do if I don't have bleeding on the 4th day of the 7-day break?

Hi I take the second month of levomine contraceptive pills, every day at 21 I take a pill. The first month after taking the pills, the period appeared on the 4th day of withdrawal, and now the second month has passed and I still do not have a period despite the fact that 4 days have passed since weaning. I made love to my partner right after the first period and there were fertile days in the calendar, would I have anything to fear? I was also sick once or could it affect something? Thank you for your reply.