Coughing?

[EasternRomioi3]

Hey guys, I don't know what's going on with my axolotl. Her water quality is perfect, she's eating, once every two days (I give her three pellets), and she's active. I have been keeping her tank around 62-64 degrees consistently and doing weekly 50% or more water changes. But, 2 Mondays ago, she puked up a worm I gave her. She's never puked before. Ruined her water quality, had to re-clean her tank, it was bad. So I gave her only pellets for two weeks and figured since I'm home all day today I can watch, so I gave her a small worm. She's a 3 year old old, about 11 inches long, the worm was about 2 inches long. She went after it, she wanted it, was very excited to get it. Then I watched her suck it in, and then "cough" for like 5 minutes before turning around and just idling now. Just sitting in the sand, breathing away, staring the top of her tank. I walk by, she turns, I walk away, she turns back to looking at whatever.

Further more, she hasn't used the bathroom in at least 7 days. She usually goes once a week but I haven't seen her go in a while. She has ultra fine sand in her tank, no pond stones, she has 2 big things of drift wood and a massive rock buried in the sand, there's no way she could have impaction, right? She has only ever eaten pellets and earthworms since I got her. She still goes for her pellets no problem. I hand drop them in front of her so she doesn't suck up any sand. I know how bad impaction is, is this something I need to worry about?