Low hcg levels at 4 weeks

TB

I’m only on day 29 of my cycle but I took an early result pregnancy test a few days ago and I got a faint positive. The doctor confirmed it with a blood test, but says my hcg levels are only 32. He wants to test again in a week to see if they go up but he says it could be a chemical pregnancy. I’m so sad thinking this pregnancy might not last. Has anyone else had low hcg levels in the beginning?