Please take your piggy off any fresh food until 24-48 until after the poos have normalised to give the gut microbiome time to rebalance. It is likely just a mild tummy upset.
Only if things don't look noticeably better again within 24 hours or your piggy is getting worse (poos are losing shape) or your piggy is suddenly going flat and doesn't want to eat at all (GI stasis), then please see a vet asap.
Switch from weighing weekly to weighing daily at the same time.
Has your piggy recently been on the lawn or been fed plenty of fresh grass?
Here is more information on tummy problems:
Digestive Disorders: Diarrhea - Bloat - GI Stasis (No Gut Movement) And Not Eating
Weight - Monitoring and Management