You could spare yourself embarrasment, if you check your supposed knowledge before posting.
Women on hormonal birth control do not have periods. If they use the placebo method, they have withdrawal bleeding in the placebo week. This is not regular period gushing out after being held in for 3 weeks. There is no retention of blood that would need to go out.
To skip bleeding, one should not just use regular prescription and skip the placebo week. Consult your doctor. There are products specifically optimised for this. Resulting in a 3 month or even 12 month cycle.
But this is with pills. And taking pills is unreliable. Hormonal implants and even injections hold up for months and years.