Not all transcripts will show AP credit. Mine won't but that's simply because I never had the scores sent to the school. Even if you do have them sent, a lot of times they will only show as credit given, not the score you received.
You can retake calculus even if you do have AP credit. Most schools do not force you to use your AP credit (I don't know of one that does). There are various reasons why one would want to take a class you already got AP credit for. For example, I retook intro chemistry because I treated it like a joke in High School and somehow managed a 4 on the AP test when I actually know nothing. Retaking that class was one of the best things I've ever done and I actually learned and enjoyed it so much that I decided to double major in Chemistry now in addition to my other major. Retaking AP classes is not a big deal so long as you're doing well in many of your classes and not only the ones you had AP credit for.