Pregnancy Calculators

Pregnancy is a biological term used to describe a woman's condition during a period of time (about 9 months) during which one or more offspring develop inside the woman. Childbirth usually occurs approximately 38 weeks after conception, or around 40 weeks after the last menstruation. The World Health Organization specifies a normal pregnancy period that lasts between 37 and 42 weeks. During a person's first OB-GYN visit, the doctor will usually provide an estimated date (based on an ultrasound chart) that the baby will be born, or the date of birth. Alternatively, the due date can also be estimated based on a person's last menstrual period.

Pregnancy occurs when a sperm fertilizes an egg after it's released from the ovary during ovulation. The fertilized egg then travels down into the uterus, where implantation occurs. A successful implantation results in pregnancy. On average, a full-term pregnancy lasts 40 weeks.If you don't want to wait until you've missed your period, you should wait at least one to two weeks after you had sex. If you are pregnant, your body needs time to develop detectable levels of HCG. This typically takes seven to 12 days after successful implantation of an egg.