

The good news is you haven’t brought all your things in yet. Don’t bring anything else in until you’ve had some time to investigate.
One bed bug, like you’ve said, could come from anywhere. If this apartment is infested you will find so many more. Give it some time to make sure this is an infestation. Do you have bites? Are there other signs? Of course the landlord is ALWAYS going to say there aren’t any bedbugs, of course they would. But give it some time, pay another month, see what happens.
If no more bedbugs show up, and you don’t get bites, go ahead and move your stuff in. If it’s infested, get out because they are SO hard to get rid of!
If you were suddenly fabulously wealthy, would you continue to work in stone, or quit and never look back?