I had blister on the roof of my mouth that randomly showed up. it ended up poping but sould i be worried?

Monitor it: Keep an eye on the area to see if it recurs. If so get to Dentist while it is there. Likely nothing to worry about - often get scrapes/cuts there from crust, crackers, chips, etc, and burns from hot liquids, sauce from pizza, etc. Good Luck.

Canker sores: is the most common oral lesions. Most ulcers, infections will clear up by themselves within a week or two. You should see your GP or dentist if the ulcer gets worse or lasts for longer than 2 weeks. Best of luck.