Girl, even once a month kailangan pa rin ng protection kasi kahit isang beses lang pwedeng mabuntis, one of my mum friends thought the same thing and ended up pregnant, haha! Honestly, it's better to talk to your OB about what contraceptive works best para sa inyo, whether pills, IUD, or whatever, kasi sila ang makakaadvice ng tama based sa health mo. The peace of mind lang na hindi aasikasuhin ang unwanted pregnancy ay worth it na talaga, no?