My DD held it together the first week, but was extremely EXTREMELY grouchy and ornery from the time she got home, until she crashed at night.
She did not cry on drop off (but she is extremely naturally stoic by nature, at least with crying). But she told me that it was very hard having to follow all the new 'rules' (and she didn't tell me this, but her Kindergarten teacher was an old hand who she couldn't dance around or manipulate as easily as she did her preschool teachers, which was a total world-rocker for her).
My DD is a kiddo who likes to know her place, and how things are ordered. Until she figured out the new order and her new place, she was very out of sorts. We were so lucky that she only had 14 kids in her class (as opposed to the 22+ that is the norm here) so it was not quite as overwhelming as it could have been, sensory wise).
Depending on the school and what experience she had prior to this, it can be a LOT to adjust to. My daughter has told me that everything "felt different" at Kindy.
I wouldn't worry about what "Everyone else" is experiencing either. To be really honest with you, I know many many many people whose kids experienced "delayed out-of-sortsness" either a month in to Kindy or after the first real break. I've seen it while volunteering in the classroom too.
Some kids take longer to warm up but then steam ahead on an even keel, some jump right in and are abuzz with adrenaline/fun changes and then crash, most are inbetween.