Worried to death! Please help

I am so worried i am going to mc. I found out i was pregnant when my pms was 2 days late. I went to my OB and he did an ultrasound on my stomach and there was nothing no sac, baby nothing. He said its cause its so early. I was only 4 weeks 6 days. My next ultrasound isnt until the 27th. im 5 weeks 1 day today and i barley feel pregnant. I've been pregnant twice and lost both my babies so i am freaking out to know if my baby is ok. I have taken test everyday since i found out i was pregnant and the lines keep getting darker.. is that a good sign that im not mc?