Checked Bag on a Stopover
 

I have a domestic trip with a stop over of a few days booked. AAA-BBB-CCC. Do I need to tell them to check to my back to BBB if I have a checked bag or will they automatically do that for me?

If it’s a few days, it will only be checked to the first destination (stopover point) automatically.

The rule is a short-check is mandatory for any connection/stopover 12 hours or more.
For 6-12 hours short-check is default but an agent can check it through.
For under 6 hours you can usually get them to short-check it if you ask nicely.

This is not a short check. OP is stopping over and not connecting. Thus, in any event, his bag will be checked to his first destination.

As to the precise question asked, even on a one-way, single-segment ticket, it always pays to verify the destination and then double check the bag tag. Trust, but verify.