I am a little confused - so you did have an ultrasound and it did show you were pregnant, but it was just showing you weren't as far by a couple of weeks. Was the ultrasound before or after the bleeding, and have you only had the one ultrasound?

If the ultrasound was done after the bleeding and it is showing there is a baby in there then you are pregnant, and sounds like your hormones are still going up, just not as fast as they should, but that can happen - it should be monitored regularly though.

Are you seeing your regular doctor?