Norethindrone periods

So o started this birth control on December 1st. I’ve had one normal month in February but outside of that I’ve had my period every other week.

My doctor said it’s normal and called breakthrough bleeding and should regulate after the first 6 months (the 6th month will be June)

Should I get a second opinion or did anyone else also experience this?

I’m really hoping it fixes itself because I can’t do estrogen again, it makes me so nauseous and sick I can’t function :((.