7 - 9 days "From the time a feilized ovum enters the uterine cavity from the fallopian tube (which occurs 3-4 days after ovulation) until the time ovum implants (7-9 days after ovulation) the uterine secretions called uterinemilk provide nutrition for the early dividing ovum" "At the time of implantation, on days 21-22 of menstrual cycle the predominant morphologic feature is edema of the endometrial stroma." Impoant facts : Oogenesis begins in ovary at 6-8 weeks of gestation.deg Maximum number of oocytes (6-7 million) are attained at 20 weeks of gestation.deg All the primary oocytes in the ovary of a newborn are arrested In the late prophase (of meiosis) till pubey.deg At pubey as a result of mid cycle preovulatory surge, meiosis is resumed and compTetedjust prior to ovulation.deg Therefore first polar body is released just prior fo ovulation The second division stas immediately after_ it and is arrested in metaphase.deg At the time of feilization second division is completed which results in the release of oocyte and second polar body. Therefore second polar body release occurs only at the time of feilisation.deg LH surge preceedes ovulation by 34-36 hours.o LH peak preceedes ovulation by 10-16 hours.o Prior to ovulation :- Follicle reaches a size of 18-20mm. - Endometrium is 9-10 min trick.o - Endometrium show triple line on USG.o Ovulation occurs 14 days before the next menstruation.deg Maximum action of corpus luteum is at 22 day of menstruationdeg (following which it stas regressing ~ 8 years after ovulation).deg In absence of feilisation and implanation the corpus leteum persists for 12-14 days.o Maximum growth of corpus lutem of pregnancy is at 8th week of gestation and degenerates at 6 months of gestation.o Feilisation occurs in the ampullary pa of fallopian tube.deg Feilised egg enters the uterus on day 18 - 19 of the cycle.deg