Why Are My Menses A Week Late?

HELLO DOCTOR-I HAD MY PERIODS ON JAN 4TH 2010 AND THEN ON 12TH FEBRAURY 2010.AND AFTER THAT IN MARCH I HAVE NOT GOT MY PERIODS AND ITS ALMOST 1 MONTH AND 7 DAYS PASSED.I FEEL VERY GIDDY AND HAVE THE FEELING OF NAUSEA AND FEEL VERY TIRED.DOCTOR WHEN CAN I DO MY URINE TEST TO FIND OUT WHETHER IM PREGNANT OR SHOULF I WAIT TILL THE END OF THIS MONTH TO DO THE TESTS IM BIT CONFUSED SO WANTED UR SUGGESTIONS AND HELP IN THIS MATTER



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