I think you would be ok to wait longer to see what the BHCG is doing I was just thinking if it was ectopic then if they knew for sure now then you would have more options for treatment over surgery.
Unlike chepie my ectopic pregnancy didn't rupture my tube which was where it was it was the general anaethetic that almost killed me.
I guess another scan maybe still wouldn't pick it up so soon after the last. My BHCG at 15DPO was 71 then it actually went down before going back up again. Because it went down thats why despite my abdominal pain they were sure it wasn't ectopic. They also said I was never pregnant and one Dr said I was barely pregnant. I actually marched myself of to ED and sat in the chair and insisted they re-scan me and thats when they discovered it which all it did was confirm what I had been telling them for 3weeks. At the moment there isn't a day that goes by where I don't think about it so you haven't made any thing resurface.
I am sure they told you if you get any pain including shoulder tip pain to march yourself of to the hospital. Once again I am praying for the best possible outcome.