Did I accidentally buy from a puppy mill?

Hi, I just brought home an 8 week old mini poodle (or maybe a mini doodle?) from Pennsylvania. The seller said they were Amish. I traveled 3 hours by public transportation to pick him up, and now that I’m back, I’m honestly starting to worry I might’ve unknowingly supported a puppy mill. They were hesitant when I asked for a receipt, they said no one ever asked for that before. (I did end up getting one). They gave almost no info about the parents besides saying they were “in a pen.” At 8:30pm. I didn’t get any proof of vaccinations or proper vet care, just a vague mention that he’d seen a vet.The puppy hadn’t been bathed at all. He smelled like wet dog and barn, like he’d been kept in not-so great conditions. His heart was racing the entire train ride back. He seemed nervous, like he wasn’t used to being handled gently or being around people much. He’s sweet, and I already love him. I plan to take him to the vet as soon as possible and give him the loving home he deserves. But I feel heartbroken knowing I might’ve supported a bad breeder without realizing. Has anyone been through something similar? Is there anything I should watch out for physically or emotionally with a puppy that may have come from a puppy mill?

Any advice, encouragement, or honest feedback would really mean a lot 💛