she wrote poss preg.. pregnant or not?

my period came on may 26 it was a brownish color @ first then gradually turned to light pink & dissapeared completely on may 28,i've had weight gain ,bloating,nausea,irritable,feeling full,ive taken a pregnancy test @ the lab on 66/7/2012 & have to wait til 6/18/2012 for results,i just had an ultrasound on 6/7/2012..when i was asked if i were pregnant i told the sonographer that my results were still in the lab so,she called & asked them for results,she didnt reveal them out loud but she wrote poss preg..what does that mean?why would they not confirm or deny a pregnancy @ this stage? what could be wrong?