Sudden decrease in any symptoms?

Has anyone had a sudden decrease in any symptoms? I went from feeling nauseous so bad all day for 3 weeks to pretty much a minimum. BUT my cravings and appetite are back. I'm 7 weeks and 2 days now. My breast are still super tender and I'm still constantly rushing to go pee. And I'm still pretty fatigued, but I have a little more energy. My first US scan said the baby was attached to the left side if the uterus instead of the center, so I'm due back on the 20th for another. I don't know if I'm just over thinking because I'm scared, or if it could be something serious. I have also had some cramping, but not too bad.

Also, I had an IUD back in 2011 that was embedded into my uterus. Doc said baby could be attached to the side due to that. But unsure.