I m 24 years old and four months ago I missed my period for two times and this was the first period missing in my life. then I ve consulted a doctor and she prescribed me menozia(norethisteron), after progestin challenge I got my period back and continued that treatment for three month, this month I supposed to have period normally without any medicine but I missed period again, expected date of period was 27november, today 29 but no period still. TSH test result was normal for me. now what should I do?