Strange meow

This morning around 5 or so Freckles used the litterbox in the bedroom. When he was done he let out a loud meow. I was semi awake and put the light on to check on him. He meowed again, but allowed me to pick him up. He seemed fine after that, climbing on the bed and laying down with me. He ate all his wet food this morning, so that's not a problem. It just seemed like a meow of pain. Is this normal?

The very important question is, was he in his litterbox making a meow of pain and did not use the litterbox, or had he finished using the box and then made a meow?

Monitor his eating/drinking/peeing/pooping very very closely. If you notice him straining in the box even the tiniest bit, or if he keeps sounding in pain in the litterbox, take him to the vet straightaway. And feel where his bladder is. If you can feel that his bladder is hard or swollen, or he seems in pain when you touch it, again with the go straight to the vet.

Just like with humans, hurting when you pee is a bad thing, but in male cats esp in can be a fatal problem if their urinary tract is blocked.

It could have been coincidental, though, and he felt pain in the litterbox, so keep an eye on him for any other symptoms as well.

It was after he was done. He's going back for bloodwork in a couple of weeks but if this continues I will bring him in sooner. He seems to be eating and drinking well which is a good thing.