Best contraceptive is oral contraceptive pills like novelon, to be taken for 21 days in a month. If has maximum efficacy. If you do not want to take any tablets then copper t is the next best option for u, once you put it and forget it. No need to take tablets every day. There is no such pill that is once in a month. Injection dmpa is there once in 3 months, but it causes lots of irregular menses.