Hcg levels

I went in for a transvaginal ultrasound and they weren't able to see anything I went for a blood test my obgyb contacted me today with my results of 57 hcg I go again tomorrow for another blood test I was wondering if anybody has ever had a low number as 57? and if so how far along where u? My obgyn said my number is pretty low so I am a little worried just looking for some insight thank you and baby dust to you. Also no bleeding