<prompt> After how many days of ovulation embryo implantation occurs?3-5 days7-9 days10-12 days13-15 days  <response>: Ans-B i.e. 7-9 days Shaws states Implantations occurs about 6th day after fertilization or approximately 20th day of a regular menstrual cycle Guyton states 10the, p 945After reaching the uterus, the developing blastocyst usually remains in the uterine cavity for an additional 1-3 days before it implants in the endometrium, thus implantation ordinarily occurs on about 5th to 7th day after ovulation 10thep. 945.But on page 936-937 of the same edition, Guyton clearly state From the time a fertilized 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 uterine milk provides nutrition for the early dividing ovum. 