Possible miscarriage???

So yesterday I posted of me bleeding and having blood clots. I went to the ER today and they did blood work and ultrasound. In the ultrasound the tech said he could not find a baby and blood work showed hcg levels are 180. Does this mean pregnancy is too early or did I have a miscarriage? Dr said seems like I had a miscarriage but didnt really explain anything except follow up with your OB. I found I was pregnant on Thursday and began bleeding on Friday. I took a pregnancy test today and it still shows I am pregnant. I'm just confused and hearr broken. Any advise or knowledge would help.