If popcorn ceiling contains asbestos, then does it mean it’s made out of vermiculite

Vermiculite on its own poses no health risk, and can be removed without concern. However, in many cases, mined vermiculite can contain traces of Asbestos, and so its removal is not recommended without an asbestos test. I would, as Scott suggests, call the testing company, and make sure that since no asbestos fibers were found, this indicates that the vermiculite used was asbestos free. If that is the case, you are good to go (that being said- wear a mask when you strip the popcorn ceilings, or you'll be coughing and hacking a lot- that dust is nasty).

Professional air monitoring is the first step: expect a bill in the range of $500 (a technician stays on site for the entire hour or so test). A little compressor draws air into a sampling can, which is analyzed in a lab. They physically look for captured fibers and can find a single fiber in a sample.

Asbestos removal is surprisingly expensive, and must be done by a licensed firm (at least in the USA). In California USA I was quoted $750 in tipping fee alone for one square foot of asbestos paper, though a bigger firm can combine with other jobs. Everything is registered and tracked. As usual get multiple bids: you may have trouble finding a firm willing to clean up after someone else's mess. The full procedure involves huge quantities of plastic, creating a negative air pressure zone where the worek is done.