For the pill, patch, ring, implant, and both coils, fertility typically returns to your own baseline very quickly once the method is removed or stopped, sometimes within days. Many people ovulate in the first cycle after stopping, so if you do not want to conceive you need another method straight away.
The contraceptive injection is different: it can take several months, sometimes up to around a year, for ovulation and normal cycles to return after the last dose. This is worth planning for if you are thinking about pregnancy.
While fertility itself returns fast, it can take a few months for your natural cycle to settle into a regular pattern. If you are planning pregnancy, starting folic acid beforehand is recommended, and a doctor can advise on timing and any pre-pregnancy health checks.