Actually the blood flow is a "withdrawal bleed" you could take the pill for months staright and never get a period unless you quit taking them.
You can fairly easily skip blood flow on monophasic pills, but triphasic pills are harder to skip on due to the change.
Many women have taken birth control and not had a period for years...
All the blood flow is a withdrawal bleed from lack of hormones..Which is why if you missed 2-3 pills you would bleed or spot.
Many women who miss 1 pill will spot, because the hormones lower.
That is how the pill works it stops ovulation!