I've never gotten a note. Been told a couple times by mgmt that I would need one when I banged on a monday or friday. Another mgmt scare tactic to try to discourage people from banging. Came back to work each time and pretended like nothing happened and was not asked for the note. Don't know about different state rules but where I live when job forces you to get a dr. note they have to come to you're house and pick you up. Drive you to the dr. And employer by law must pay the co-pay.
More intimidation. One local gung-ho manager used to actually drive to your home if you called-in sick. One day, I called-in, because I had the intestinal flu and basically couldn't get out of bed without either throwing-up or soiling myself. So,

rings my bell, and I come to the door, obviously quite ill. He tells me that "you look OK" and that I "should have come to work". Then he says he expects me at work the next day,
with a note. Then, he turns, and walks back to the FedEx van he drove out.
First, I called HR, and told them I was being harassed. Next, I phoned the Managing Director, and then I called my doctor and asked him to write me a note for a full week off due to "stress", which he agreed to do if I came in for an appointment and he evaluated my condition.
When I returned to work the following week there was a letter of apology from my manager, who had been told to never go to an employee's house again,
and he got a letter.
I only wish I had the German Shepard that I have now, because I would have let him chase Mr A-hole back to his van. He's trained not to bite.