My Wife Is Taking Dronis30 Last Four Months Back. But

My wife is taking dronis30 last four months back. But in this fourth month her date is delayed. Her date was 11th. But today is 14th and date is delayed. In this month she forgot one tablet. Is this any reason for delayed period Or any risk of pregnancy. we are worried, plz tell me and I ask one more thing, the dronis30 tab course is for 21 days and we start it after fifth day of mansuration. Total 26 days. The gap of four days we didn't used any precautions. Is it safe or not?? Plz answer me.