5 weeks 2 days, symptoms disappearing?..

I’m 5 weeks 2 days pregnant and up until today have had normal pregnancy symptoms; full/sore breasts, fatigue, frequent urination, mood swings, increased sense of smell. Yesterday I went in for a vaginal ultrasound and they didn’t see a gestational sac, and they said they should had been able to see it by 5 weeks. The nurse practitioner told me she thinks I may be having a chemical or ectopic pregnancy. I went this morning to get blood work done and have to go back again in two days and get it done again then they’ll compare it and see how things are looking and go from there. Anyways I noticed today that all the symptoms I was having have pretty much completely disappeared and I don’t feel pregnant. My breasts were full and extremely sore and now they’re not full and not sore. My sense of smell seems normal. Still tired but I think that’s because I couldn’t sleep last night. Has anyone been through something similar? If so, how did things turn out for you?