Hi!
Pregnancy is a time of a great deal of worry. There is just no way around it! An irregular sac could be a sign of an impending miscarriage. But if there is no bleeding or cramping there is still a very good chance that everything will be OK. I will warn you in advance that very often when people go in for their six week scan, they see a fetal pole with a low heart rate. Usually around 90 bpm. They then have to worry about that for another week until it increases to the range of 140-170s.
There isn't much to do except take good care of yourself and pray (if you do so).
I certainly hope that everything looks good next week!
Dr B
my wife is about 4 weeks along and today we had to go to the er do to clots, the u/s found a small mass within the sac and it had a h/b of about 80bpm. at this stage is this a main worry?