Hcg blood work normal or low?

Amber • My baby girl born December 20th ‘19 🥰

I woke up this morning with stabbing pain in my abdomen so I called my dr and they got me in for an ultrasound right away and blood work. The ultrasound showed no pregnancy but according to my last period I would be 5 weeks and 6 days today, so 6 weeks tomorrow. They were concerned for an ectopic pregnancy but saw nothing in my tubes either. I have also been having light brown discharge as well but no cramping in uterus. The pain has all subsided but still light brown spotting. My hcg blood level was 767 and according to my dr that is in the normal range but it makes no sense as to why they didn’t at least see a sac. Is it possible for the pregnancy to hide? My levels seem so slow for being 6 weeks.. I go in tomorrow for another ultrasound and more blood work. Has anyone had these levels and still had a healthy pregnancy or had a pregnancy hide ?? Otherwise I have already miscarried but have yet to start bleeding yet and will know for sure tomorrow if my levels are dropping. Any input about this would be great!! TIA!!

UPDATE: It is an ectopic. They found baby on my ovary which is extremely rare they say. They are trying Methotrexate first before going straight to surgery. High success rate for the injection. Since I’m young they want to limit my losing anything!