Tube size question

I had to change the tube in my rear roadbike tire yesterday (700x28) and just used the tube my LBS put in my saddle bag like 2 years ago. I don’t remember the size but it seems like it was a 25.
Am I gonna be fine on that or should I switch back to a 28 ASAP?

Totally fine, no issues at all. Think I’ve had a 25 in my 33c cx bike for about year!

Awesome. Just run lower pressure?

I don’t even think about it, just treat it like any other tube. I’d put in whatever pressure you usually would with that tyre.