I also had the bleeding, had u/s and they seen nothing and said I had miscarried. Although my hcg kept rising so they then said I had an ectopic. So went for abother u/s, was about a wk later and I had a healthy sac and bub with heartbeat, was then about 6wks. So would have been about 5wks when they could see nothing. Now my little man is 17mths!! I hope you get some answers soon xx