I have had the para-gard IUD for one year and have been very regular (every 28 days) the entire time. This month I missed my period and am 2 weeks late. I took several pregnancy tests including a blood test which were all negative. I have mild cramping, scant brown discharge, and an abnormal lower backache. Does this sound like pregnancy to anyone? I feel a little different in general. I am concerned about a possible ectopic pregnancy? Could that be possible with a negative blood test?