Hi , My Gf Menstrual Cycle Is Not Normal It

Hi , My gf menstrual cycle is not normal it is one and half month over but no period(those days) occur. We tried preganews it showing negative result what can we do...??..can U suggest some pills for abortion like as MTP or d-pill ...and their working.Is these pills are harmful if preganews test is negative and u still taking these pills.Plz tell me asap
Thnx
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