I have just applied for TSA Pre-Check and will have my appointment in a couple of days where I show the officials my personal identification documents. I have already booked a flight at the end of July through Delta. Can I use TSA Pre-Check on this flight, despite having already booked it?

Tag Request: I think that a new tag should be created for tsa-precheck(or tsa-pre-check) since there are about half a dozen questions about the program on this site. However, I do not have enough reputation to create the tag. Could someone with more rep please create the tag and add it to this question?