how do I know if I am safe today by using calendar method?

Kng regular mens ka safe ka po bago ung mens mo. Kya kse mabuhay ng sperm for 10 days. Ang ovulation nmn e 14 days after ng 1st day of mens. So kng after ng mens mo nkipag do ka mlaki chance mabuntis. Kya dpat before mens.

Kung regular ung period mo you can use the app maya. I lo-log mo ung period mo then siya ang mag sasabi kung kelan ka safe or fertile.