Anyone have advice

It’s been just over six years since I was last pregnant, really closer to seven. I don’t remember feeling this tired and gross feeling. I’m nauseous, but not to where I’m throwing up, constantly hungry, having cravings, but once I eat, I’m back to feeling nauseous and like what I ate is coming back up but it doesn’t. I have my first appointment tomorrow, and hoping for a scan. I’m either eight weeks tomorrow or 11/12 weeks(my periods were all weird in December which is around when I got pregnant). I had a three day period around December 28th which is what I’m basing everything off of since I took a test December 26th and it was negative. But my tests(7 I think) that I took in January came up positive right away and I was maybe three weeks pregnant going off of December 28th. My last pregnancy was twins, and was a rough go for most of it. I’m also already showing, which is another reason I’m thinking I’m farther along. Anyone else have issues with tests saying negative?