Student or Learner
I'm sorry about back there.
Didn't used to.
Please try to put some system into your thread titles and posts, NewHopeR. Your post itself is meaningless - there is no context.
I imagine that you are asking about the form 'didn't used to'.
That form is incorrect, but surprisingly common. Some people feel that the correct for is 'used not to', though not many use that today, preferring 'didn't use to'. 'used to' however is an unusual verb (there is no present tense) and some people feel that its negative must be 'didn't used to'. In speech, 'didn't use to' and didn't used to' sound the same, which perhaps helps the confusion.