Medroxyprogesterone 10mg no period...Could I be pregnant?

Is it possible I'm Pregnant??


I was prescribed to take medroxyprogesterone 10mg for 5days. I started on Jan 14-Jan 18, 2012. Today is Jan 27th and my period hasn't come on yet. My ob/gyn told me if my period doesn't start in 2wks(Feb 1st) to come back in because something else could be wrong. I was already tested for PCOS and I dont have that. My questions are 1. if my period doesnt come on by wed(feb 1st) is it possible I'm pregnant because we are definitely ttc and been very sexually active? 2.how long after taking my last pill on jan 18th does the medication(medroxyprogesterone)stay in your body? I ask because I've been experiencing pregnancy symptoms....my nipples are very sore to touch and are hard more then normal,i have nausea on and off during the day,i have lower back pain that comes and goes,and its like one minute i'll be fine then the next i have heat flashes I'll be hot out of nowhere. My boyfriend thinks I'm pregnant too because his eating habits have changed, he's more tired and has been having alot of bowel movements. Any advice or feed back is appreciated.