Miscarriage😔

I️ was almost 5weeks pregnant. I️ was at work Saturday and had a lot of bleeding so I️ went to the ER. It was around 11pm and they did an ultrasound but did not see anything which was expected. I’ve had a lot of early symptoms already. They did a blood test and said it was negative so he thought I️ had a miscarriage because I️ had 4 at home positives on different days. Is there anyway I’m still pregnant and it didn’t show up on the blood test because your levels aren’t strong at night??