I don’t think you have anything to worry about!
Quoted from SOA (source: https://www.soa.org/Education/Exam-Req/Exam-Day-Info/edu-grades-exams.aspx)
“The unofficial instant pass/fail results received by candidates after they complete a CBT exam have been extremely reliable. Since this practice began in February 2007 the SOA has administered CBT exams to tens of thousands of candidates. In all that time there was only one instance, very early in the transition to CBT, where the unofficial instant pass/fail result did not match a candidate’s official final score result. Candidates can be very confident that their unofficial pass/fail result will match their official final scores.”
The feeling about having to retake is fairly common and could be due to:
1. Pilot questions (questions thrown into the exam but not counted for grades)
2. Luck (You might have guessed some right!)
Anyway, congratulations! Let go your worries and go ahead and plan for your next exam!