Potty training regression - should I be worried?

So we had a good run with our 3yo - was doing great for like 2 months, then bam, accidents everywhere again. New sibling arrived 3 weeks ago so timing makes sense but I don't want to make a big deal about it or make him feel bad. How long did this last for other people's kids? Should we just go back to pull-ups for a bit or stick it out?