I had an IUI on 3/30 so we are almost 100% when conception occured. I had an ultrasound last week when I supposed to be 6 wk 2 days...no baby to be seen, just sac/yolk sac. I went back today and the baby and HB were seen, but baby is measuring one week behind (only 4 mm right now). The heart rate was 93beats per minute. I have to go back Monday for another ultrasound to see if the baby is growing appropriately. Does anyone have a similar experience and had everything turn out fine?