If you don't have a nice, obliging vein that they can see pop up or feel, it's quite common, especially if you're a bit dehydrated at that point.
One way of bringing them up is to very, very lightly stroke along one as though you're tickling it - the automatic nerve response causes it in response to the sensation. And drink plenty for a few hours beforehand.
Then, you can get a vein that decides to jump out of the way - had that once - and once, the poor nurse (not phlebotomist, they had nurses in the clinic) caught a tiny nerve which made me yelp for the first time since I was about six.
The worst one was a phlebotomist at the local hospital, though. She was brutal, always picked the smallest gauge, so thickest, needle and jammed them in - so much so, people who went regularly for tests would look to see who was next and nobly allow somebody else to go in front of them. I thought 'oh, how bad could she be?', smiled, told her I was on lots of steroids (which meant I usually had a small butterfly) and her response was to ram what felt like a chopstick into my arm, which promptly went jet black for the next month as she did a through-and-through. The consultant was not a happy person when I went back to clinic and for the next appointments, we found that they'd got a dedicated phleb who was great, but would side eye her chair at every yelp. She then disappeared altogether. Shame, that. She could have been a fantastic vampire killer.