How long does THC stay in the body?

Hello! To start im a 20yr/o female, 5’6 and about 150lbs. I have been smoking daily for about 3 years, I mainly use pens though I recently ate edibles as well as smoke flour about once a week. I have quit once for a T break about a year ago for 3 months however I didn’t end up testing myself to see if the thc had left my body. I am now trying to enter a schooling program where they need a clean panel test (urine) in order to be accepted. I have stopped smoking since last night and have been over hydrating however online sources just keep saying “chronic users may take longer than 30 days to report clean” giving me no window on the longest amount of time it would take naturally. If you have had a similar experience how long did it take you to get clean? I’m kinda against getting fake pee due to the fact that I could get into some sort of trouble for fraud. My test could be anywhere from may- July, should I be worried? Is there any system where I can guesstimate how long it would take? Thank you!