This does happen sometimes because all of our sex organs work together and removal of any one part or procedures that affect their functioning (such as tubal sterilization or
removal, hysterectomy, ovary
removal, endometrial ablation) can throw everything out of whack. Have you considered taking birth control pills to regulate your cycle?
I cannot speak for the remaining ovary being "pushed back" but things can get displaced to some degree when you have surgery.