You may regret getting into an untidy bed for a short time (4)
I believe the answer is:
debt
'you may regret getting' is the definition.
I can't judge whether this defines the answer.
'an untidy bed for a short time' is the wordplay.
'an untidy' is an anagram indicator.
'for' is a charade indicator (letters next to each other).
'a short time' becomes 't' (abbreviation; 'short' suggests a short form).
'bed' with letters rearranged gives 'deb'.
'deb'+'t'='DEBT'
'into' acts as a link.
Can you help me to learn more?
(Other definitions for debt that I've seen before include "Something owed" , "Financial problem?" , "Sum of money that's owed" , "The state of owing something" , "outstanding" .)