Mini-Pill Question

Kati

So I’ve been taking the mini-pill since 7weeks postpartum, I’m now 8.5months pp. I was put on it due to getting menstrual migraines on the combo pill. The kind I’m taking is Norethindrone, but the generic version. Started out with the generic version called Nora-BE which was going fine, no problems or anything. I recently got this refilled and noticed on the package it said Heather .35mg which is a different form of the off brand. I’ve been taking it two weeks, didn’t get my period, have period like cramping, lower back pain, nausea, dizziness, my left ovary feels like it hurts when I don’t have the cramps, and I’ve gained 5lbs in the last week. What the hell????? Is this because of the switch of the generic birth control, or something else...