First of all this is the past form for the verb "يجني"
-This is the three froms of the verb (I'm explaining using the speaker pronoun "I" because it's a part of your sentence)
Past: أنا جنيت
Present: أنا أجني
Future: أنا سأجني
-well, if you try to translate it in the dictionaries you'll get the meaning of "جنيت"
is "harvest" or "gather [full-grown fruit]". and that's one of it's meanings.
the meaning what you want is to commit something wrong which is not allowed by law, decency.....
-Maybe there isn't a literal translation word so the translation is: "Did I do did something makes anyone upset" or something like that....
- There is another ramified name which is "جناية" which means "felony".
I hope that'd help you.