I cant take estrogen

Hi Dr Redmond,
I am a 35 year old woman and experience migraine headaches with aura therefore, doctors have told me I can not take birth control that contains estrogen. Recently I was told I can use Mirena and had it 'done' about two weeks ago. I have been using 5% Minoxidil for about 2 years and it seems to help?
What would your recommendation be for those of us that can not take estrogen and should I continue on Mirena?
Thank you in advance for your response!