Norethindrone
"I've been taking this pill for over a year now and the only side affects I've experienced are spotting and not exactly knowing when ill be getting my period. If I don't take the pill within my hour time frame, I'll usually encounter some spotting or even starting my period. I have migraines and I've found this pill to work really well for me. Other than that I feel this pill works good, but then again every brand of pill effects people differently."