menstrual cycle being off after removal?

hello this is more for the ladies that have gone through this process… so i got mine removed on august 24th &’ always had my cycle before that never missed one but now sept is almost gone &’ i’ve basically already missed when i should be getting it. i’ve taken multiple pregnancy tests &’ have all came out negative. theirs only 5 days left til this month is over &’ i’m wondering now if the tests are coming out negative could it be that the surgery has caused a disruption. has anyone else gone through this after surgery