Concerned about ectopic

I’m concerned I may have an ectopic pregnancy. I went for a scan a week and a half ago (I wasn’t sure how far along I was) and they saw what they think is a gestation sac measuring 4 weeks 5 days in the uterus where it’s supposed to be. Since it was so early they said they cannot rule out ectopic. I am now 6 weeks 4 days according to their calculations and I don’t go back for another ultrasound until the 11th. I am very nauseous as of today but I’m concerned because I have shoulder blade pain that radiates to my arm pit. Or maybe it’s arm pit pain radiating to my back. I’m not sure but either way I am so much anxiety I don’t know what to do with myself. Aside from the pain I have had diarrhea all day today, yesterday I was constipated terribly. They drew 2 separate hcg levels and the dr said they are rising “the way they should”. Should i be worried about ectopic???