Help!!

[Chelsie01]

My LMS was 12/14/2020, and I got a positive pregnancy test This past Sunday! I went into the ER last night because I had mild cramping (no blood) for a day or two, and they said my levels are at 556hcg. Puts me at 5 weeks. I am confused and my office won’t see me until Monday to even get blood drawn despite me saying they strongly encouraged me getting my hcg retested. Can someone help me understand is this normal to be at 556 at like 4 something weeks even though they said I’m 5 weeks and “low”? Note to add this is my 3rd pregnancy with 1 living.