Does Synthroid act as a birth control?And cause migraines.

I have read the warnings and such about best not to become pregnant while on this medication and inform Dr.  to adjust rx if it happens.  Actually am taking generic form of Synthroid.   I have never had a positive pregnancy test result from any brand of kit over my adult hood.  Also same symtoms as Poly Cystic Ovary Syndrome, are these side effects from  my medication or is it hormones, also causing my migraines monthly?   At first, thought I was pre menopausal given the chin, neck hair and severe mood swings between cycles.  I doubt being bipolar causes hair growth? lol    I can't afford any specialist, yet underqualified for medicaid etc. I fall between cracks of govt. healthcare system.