Can the delay in menstrual cycle cause disease or infertility? btw the girl is virgin still?

What sort of delay? Are you talking about late onset of menarche - when a girl starts her periods? Are you talking about useing the contraceptive pill to delay a period which is due to start on an inconvenient date? Or do you mean a "late" period, which has not arrived on the expected date?

If a girl doesn't start her periods then eventually a doctor would investigate why she hadn't. There MIGHT be a problem with fertility if a girl doesn't enter puberty properly.

Taking a pill to delay a period will not cause disease or infertility, and missing or having the occasional late period is not unusual in younger girl, or in girls who have been dieting a lot, exercising a lot, or been under stress or had a change in life circumstances. This sort of lateness is not a symptom or cause of disease or infertility.

No. Each person is different.

And young women who are especially athletic...and this includes ballet dancers...frequently have a delayed onset of menses.