4 days late

February during my ovulation week I had very heavy bleed and the following month my period was right on time which was March in that month I had heavy bleeding during my ovulation week . And April again I got my pd on time but in April I started using PreSeed with my fiancé during my ovulation week I had very light spotting for 2 days and it was only when I wipe was when I seen it . And now my period is 4 days late . Now can PreSeed affect you period ? Or can I be pregnant ? Help