any advice would be great!!

Ok so I am 11 weeks according to my dr I've not yet heard a heartbeat, not yet had a scan nothing. I don't pee loads, I have niggles in my boobs I have major constant nausea still and mega tired n awful constipation but I have major anxiety like how do I know my baby is ok? How do I know it is alive n doing well? I feel sick cause I'm constantly worrying about my scan n going n seeing nothing in the sac or not having a hb I'm super scared. I have had no bleeding n no cramps last period started 28th July but nothing since... Am I being over paranoid? I just wana c my baby n know it's ok