Hello, and welcome!
If you completed applications, but never had an in-person interview and/or submitted the appropriate paperwork, you might not be enrolled in Precheck; however there are two ways you can find out:
Go to this webpage, below and enter your information, then see what information it yields (if you are enrolled, it would give you your KTN (Known Traveler Number):
You can also call Universal Enrollment Service at ***-***-**** and ask them if you are enrolled.
If you filled out a pre-application form at Customs and that is still on file, you would only have to finish the process, have your interview and then wait to see if you are accepted.
I hope you found this helpful, and if so, please let me know and/or provide a positive rating, as that is the only way the site recognizes me for my assistance. Thank you very much!