
I too would request to have betas done, it will tell you pretty definitively what is going on.
Finding out on Oct 3 doesn't leave much wiggle room for it to be too early you would have been at least 3.5wks to show + on a test, so 4wks later could put you around 7+wks. Did they do a transvaginal u/s?
Anything is possible though! A friend of mine went in at 10/11wks and didn't have a heart beat. She wanted to miscarry naturally so just waited. She still hadn't started miscarrying 2wks later so she scheduled a D and C. She asked for an ultrasound before the procedure because she just needed closure. And there was her baby kicking and squirming, measuring exactly as he should at 13wks.