As Inky posted above, it is a non-issue. The 4 month petition validity is the time during which your fiance should have the interview. Since that already happened, there should be no problems there. Just in case, if they ask you to submit additional evidence, I would submit a letter stating that nothing has changed since the time that you submitted your petition and that you and your fiance still remain eligible and have intentions to marry once your fiance comes to the U.S.
VisaLover got a reaction from jaymee in Had Interview - Embassy Still Reviewing but my I-129F petition expires in 3 weeks!!!