You are still not pregnant actually. This is the time you should have sexual intercourse with your partner without protection. By the end of this week, you can have a fair chance of fertilization of your egg after ovulation.
As you are not pregnant till now, there is no fetal development.
Your body starts preparing itself for ovulation. The uterus is building up a lush new bed of blood rich tissues called the endometrium that can harbor the fertilized egg. One of the ovaries is preparing your eggs until one egg is ready for release. Your body secretes Follicle Stimulating Hormone that matures the egg and makes it ready for release. At the end of this week or generally on the 14 th day of a 28 day menstrual cycle, you will have ovulation or an egg is released from one of your ovaries. You will not know when ovulation occurs except for an occasional cramping pain in some cases. The egg reaches to the fallopian tube where it comes across your partner's millions of sperms that travel from vagina. One of the sperms become successful in penetrating the egg and fertilization occurs.
Generally at the time of fertilization, the gender of your baby is determined. Total 46 chromosomes are required to make up the gene of your baby. But only two of them, called the sex chromosomes, one from the egg and another from the sperm can determine the sex of your baby. Each egg has an X type of sex chromosome and each sperm has either an X or a Y sex chromosome. If a sperm having an X sex chromosome fertilizes your egg you will have a baby girl. And if a Y sex chromosome fertilizes the egg you will have a boy.