Confused

Tested positive at the hospital this weekend late Sat night with 11 hcg. Took a home text this morning and it says not pregnant? Breasts are sore, I'm crampy/bloated/gassy. I had a few (literally, a few) drops of blood earlier today. Thoughts?! Could my hcg not be high enough? Dr at hospital told me he thought I was literally only a few days pregnant. Going to ob next week.