Ectopic or not?

I had my BFP on the 30th July after 2.5 years trying and taking fertility meds. Over the last week, I had some minor cramping in my left side which got worse on Friday so I went to Emergency Care. The pain has subsided now and I don't think I've had any other symptoms really apart from nausea and a little backache. I'm approximately around 5+5weeks so I have a scan on Thursday to see if I am having an ectopic. I had my Hcg levels taken and it was in the 4000's. Anyone had anything similar and it be okay? I'm so worried :(