Don’t forget we can also use the negative ‘shouldn’t‘ when we give advice or make a suggestion.
“You shouldn’t eat that yogurt, it’s been in the fridge for 5 weeks.”
“Mike shouldn’t drink too much at the office party on Saturday. He might say something stupid to the boss like last year!”
Shouldn’t plus ‘have‘ can be used to show regret. Show that you feel bad because of something you did.
“I shouldn’t have eaten so much pizza at dinner! Now I have a stomach ache.”