Fingering during period can cause next period delay?

No: Masturbation does not cause period irregularity. Irregular periods can be caused by stress, weight gain/loss, too much exercise, hormonal imbalance, ovarian cysts, etc. If you have had unprotected sexual intercourse with a man, a pregnancy test will be positive as early as the first day of your missed period. Otherwise, if the irregularity persists, contact your regular Dr for a full physical.