Low HCG Levels? (Dates & levels at the bottom)

I found out I'm pregnant today & just confirmed with doctor. My HGC levels seem very low according to the Doctors chart but the charts I google seem way lower compared to the chart my Doctor goes off (for eg his chart says around 1000 for 4 weeks & the ones I have googled are all about 500 or less) unless in reading them wrong. He wants me to re test in a few days but I'm just looking for piece of mind... I have had miscarriages in the past when I was younger so I don't remember the levels but I'm really worried! Also I still feel "normal" Doc asked if I felt sick etc 😳
My last period started 1st August & ovulation test was positive on the 13th August my levels are 511
(In doctors chart 1-2 weeks 50-500 & 2-3 100-5000) he has told me I'm 1-2 weeks & circled it.. I thought I was meant to be 4 weeks almost😳
Sorry it's so long.. Thank you so much in advance!