Kira-kira due date pregnant

Contoh:
tarikh akhir awal period; 9 . 7 . 2011 
** tambah 7 . 3
= **jadi 16 sbb 9 + 7
= **jadi 4 sbb 7 - 3
tarikh due date; 16 . 4 . 2012
putripuzzle : let me be me