Hai how many days have to calculate our period cycle. Because last month I delay period for 12 days. I checked upt negative. Day 13 my period came. This month my period delay 4 days. How
Use period tracker apps. Its more easy. And is your period regular or irregular? If irregular, better use OPK for know when ovulation day..
Use opk sis. Seems like you have irregular period cycle. Opk is more accurate than apps