3 Things You Don't Need To Do

• Worry about that drink you had before you missed your period. It takes about seven days for the fertilized egg (zygote) to travel through your fallopian tube and implant in your uterus. The placenta begins to develop at about 12 days after conception, which is just before your period is due. Before then, there's no e xchange of blood between mother and baby.

• Worry that having morning sickness will rob your baby of nutrients. Generally, nausea and vomiting taper off by the end of the first trimester. During much of that time, the embryo and, later, the fetus will leech what it needs (which isn't a lot) from your body. Just make sure to take a multivitamin containing at least 400 micrograms of folic acid daily.

• Worry that something you do will cause a miscarriage. Most early miscarriages are the result of chromosomal abnormalities within the developing embryo; many occur even before you know you've conceived. Smoking, drug use and very heavy caffeine consumption increase miscarriage risk, but normal activities, including exercise and sexual intercourse, do not. Once the fetus's heartbeat is detected by ultrasound--usually at around six weeks of pregnancy (counting from the first day of your last menstrual period)--the risk of miscarriage drops to less than 10 percent.