I've been on the same bc pill for a year; never had spotting until now. i got my period 2 weeks early. i just started using miralax (polyethylene glycol). correlation?

Oral contraceptives: it is very unlikely that myralax will interfere with your birth control pills. If the problem is persistent you will need an evaluation and possibly a change in your pills.

Menstrual period: Not likely. Young women can have irregular periods at times, even on BCPs. May be due to stress, fatigue, or recent illness. I would not be concerned unless it persists. Be sure that you did not miss any pills and that you took the inert pills at the right time, or discarded them on the right days.