No HCG but still pregnant

Hi everyone! So I was wondering if anyone knows anything about or have it, if you can still be pregnant and not have any HCG? I’ve taken 20 pregnancy tests and 2 blood tests and nothing. I have also missed my period for 2 months now, I read online that plenty of woman have been pregnant and just don’t produce HCG. If someone could help me understand if it’s an actual thing that would be great! Or if it’s happened to you

I’ve also had almost all the pregnancy symptoms along with this