6 weeks fetal pole no heartbeat (yet)????

I have been pregnant 5 times and have had 5 births.  I found out I was pregnant with #6---  Went to OB  who stated I was 5 weeks.  Today had U/S to get dates.  The tech stated that the fetal pole measured 6 weeks but was unable to get a heartbeat.  The tech wrote on my sono sheet to come back in 2 weeks for viablitiy.  That stung.  I know that my HCG levels in my first trimester are always low and have been for every pregnancy so I can't count on that.  Left the office unsure and sad---was counting on the sound of the heartbeat.  Reading prior posts sounds like I may still be too early--but left with the uncertainty hurts more.  If anyone has gone through this please post...Thanks in advance.