Grim news

Went in for our first ultrasound this week.  I was 8 weeks 3 days according to my last period but they have beet very irregular.  The doctor said I was only measuring 6 weeks and that the heartbeat was slow at 72.  Anybody else have this happen and the dates were just way off. Trying to keep my hopes up for my next ultrasound on Thursday.  My ultrasound was This past Wednesday and I haven't had any cramping or bleeding.  Just super stressed!