Taking too many plan b pills, is it dangerous? or harmful?

Don't worry: The worst that can happen is that your period schedule gets disrupted but otherwise they are very safe.

Can be: Plan b had high doses of estrogen with a sudden drop back to your current levels to induce a period or micro-disruptions in the uterus to help prevent/reject implantation. Frequent swings in estrogen will at a minimum make your cycles very irregular. Additionally if you are using Plan B that much your are taking a lot of chances with exposure to potential stds, hiv, hepatitis and hpv.