1) About three days after conception the zygote now consists of 16 cells and has normally reached the junction of the fallopian tube and uterus. About five days after conception a cavity appears in the center of the zygote and the grouping of cells are called a blastocyst. The blastocyst has started to travel down the fallopian tubes and has started to attach itself to the endometrium. The cells inside the blastocyst start forming an embryo. The outer cells of the blastocyst start forming the placenta. Nine to ten days after the conception, the blastocyst has fully attached itself to the endometrium and primitive placental blood circulation begins. Twelve days after conception, the blastocyst has started to produce hormones that can be detected in a women's urine. Thirteen days after conception a primitive streak appears and will later develop into the fetus' central nervous system. Three weeks after conception, the embryo is about 1/12" long, the size of a pencil point and its heart begins to beat about 18 to 21 days after conception. At four weeks, the embryo is about 1/5" long and the structure that will develop into a head is visible, as with a noticeable tail. The embryo has structure like the gills of a fish in the area that will later develop into the throat.
2)The physical changes that might be going on with the mother would be that she begins to produce a hormone called HCG which is critical for healthy development of the embryo and fetus. Also the mother experiences swelling of her breasts and have nausea and changes in their appetites. Also as the pregnancy continues, the placenta, amniotic sac,and umbilical cord are formed. As the pregnency continues the mothers uterus and abdomen grow and her hips begin to widen. As the baby grows rapidly, the mother's uterus expands and sometimes the mother can get stretch mark on her skin and can experience idigestion problems, as well as heartburn. As the time for delivery gets closer, the mother can have an early form of milk called colostrum leak from her breasts. Some of the emotional changes that the mother and/or father might go through would be they would feel anxious about becoming new parents along with being nervous, excited, scared, happy, and every emotion you could have, the mother and father will experience before their baby is born.
3)Some steps that both mothers and fathers should take would be to see their doctor regularly with check-ups, to eat healthy and get plenty of exercise, stay positive, try to breathe clean air, and be careful when traveling. Mothers should not eat junk food, fast food, certian types of fish, and extra vitamin supplements. Also mothers and fathers should not smoke. Mothers should not drink, take drugs, and they should try to aviod smelling paint fumes, household cleaners, or anything that has to do with pesticicdes.