You can make sure that doesn't happen (if it's not too late) by using sources of questions that you know do not include the questions from the official practice tests, aka the GMAT Prep tests.
Another thing to be aware of, by the way, is that some test prep company questions are essentially "lifts" of questions from the official practice tests. The existence of such lifted questions is one reason why people score much lower on the actual GMAT than they had on the official tests. The study materials they have used have tipped them off to the answers to the questions on the official practice tests.
You can avoid using the questions from the official practice tests by using only high-quality third-party questions or questions from the OGs
https://www.efficientlearning.com/gmat/ or Official Practice Questions sets 1 and 2
https://www.mba.com/exam-prep. On GMAT Club, you can tell which are which by using the tags.
Since you have already seen some questions from the official practice tests, when you take the tests, if you see a question have already seen, take a couple minutes to work your way to the answer to do as much as you can to preserve the test experience for yourself.