should i be worried?

so a couple weeks ago i went to the ER with some pretty bad cramping and wanted to make sure everything was okay. i was 4weeks pregnant at the time. my hCG was at 645 but they did an ultrasound and didn’t see anything which i heard is normal. the doctor immediately assumed ectopic and called for a second opinion. the second doctor did an exam and said i should be fine and that it doesn’t seem ectopic and that i might just be too early. i cant stop worrying though. i’m now experiencing bloating and my bellybutton is turning into an outie (nothing alarming at all) but i want to see what you ladies think. should everything be fine?? i have an ultrasound on march 6th at my 6weeks.

please respond!! is everything okay??