February 1 you get pregnant., NOTE; most important to know before you apply the formula first you must know your LMP or last menstrual period this is ( February 1) my answer,.. So based on your EDC or expected date of confinement/due date that is NOV.8. THE FORMULA IS THIS; from january to march( +9+7),april to dec(-3+7+1)... I apply the formula
LMP ; (2ND MOS) FEBRUARY / 2 1
+9 +7
...
(11MOS) NOVEMBER 11 8
LMP ; (2ND MOS) FEBRUARY / 2 1
+9 +7
...
(11MOS) NOVEMBER 11 8