What Could Be The Reason To Miss My Period?

I am on birth control and did not miss any pills. I did miss my period this month, it has been 2 weeks since i was suppose to start and I have taken 3 at home pregnancy test and they were all negative. I did however stop taking my prozac as well as my thyroid medicine about a month ago with our consult, i just forgot to get it refilled. Could there me some relevance from me not taking my thyroid and anxiety meds and me missing my period?