HCG levels???

So based on my app I should be 4 weeks and 6 days today. I took a blood test Friday and today they told me I'm probably not that car along. my HCG level was 162? It was in the 160s not too sure exactly what number. But it's kinda freaking me out because I miscarried a few months ago and they thought I wasn't that far along back then either. is it normal??? Dx I want to cry so bad I don't want to lose another baby. UPDATE I just found out it was 124 HCG. UPDATE I got really nervous and called to ask if I can get another blood test done. I just got off the phone with a nurse with my results. 858 HCG level!