Possible chemical pregnancy?

Has any one experienced what they think is to be a chemical pregnancy but was too late testing to catch it? I was 5 days late and started bleeding this morning. My bleeding is very heavy and I’m having a lot of clots. Since Sunday I have been having the worst cramps of my life. Doubled over in pain, not able to work etc. Today I started vomiting as well. I had a miscarriage when I was 17 and it’s similar symptoms. I went in for a blood test yesterday that was negative. Is it possible we just didn’t catch the HCG levels going up before losing the baby? I’m not fully sure how this works. I messaged my Gyno to ask as well. My periods are pretty regular maybe a day late or early here or there but nothing like this cycle.

Thanks!