The proportion of cases of denial, persisting until delivery is about 1 in 2500. Conversely, some non-pregnant women have a very strong belief that they are pregnant along with some of the physical changes. This condition is known as a false pregnancy. Physical signs
Most pregnant women experience a number of symptoms, which can signify pregnancy. A number of early medical signs are associated with pregnancy. These signs include:

the presence of human chorionic gonadotropin (hCG) in the blood and urine
missed menstrual period
implantation bleeding that occurs at implantation of the embryo in the uterus during the third or fourth week after last menstrual period
increased basal body temperature sustained for over two weeks after ovulation
Chadwicks sign (darkening of the cervix, vagina, and vulva)
Goodells sign (softening of the vaginal portion of the cervix)
Hegars sign (softening of the uterine isthmus)
Pigmentation of the linea alba – linea nigra, (darkening of the skin in a midline of the abdomen, resulting from hormonal changes, usually appearing around the middle of pregnancy). Darkening of the nipples and areolas due to an increase in hormones. Biomarkers
Pregnancy detection can be accomplished using one or more various pregnancy tests, which detect hormones generated by the newly formed placenta, serving as biomarkers of pregnancy. Blood and urine tests can detect pregnancy 12 days after implantation. Blood pregnancy tests are more sensitive than urine tests (giving fewer false negatives). Home pregnancy tests are urine tests, and normally detect a pregnancy 12 to 15 days after fertilization.
The number of pregnancies in women aged between 15 and 44 is 133 per 1,000 women. About 10% to 15% of recognized pregnancies end in miscarriage. In 2016, complications of pregnancy resulted in 230,600 maternal deaths, down from 377,000 deaths in 1990. Common causes include bleeding, infections, hypertensive diseases of pregnancy, obstructed labor, miscarriage, abortion, or ectopic pregnancy. Globally, 44% of pregnancies are unplanned. Over half (56%) of unplanned pregnancies are aborted. Among unintended pregnancies in the United States, 60% of the women used birth control to some extent during the month pregnancy began. Terminology
Associated terms for pregnancy are gravid and parous. Gravidus and gravid come from the Latin word meaning "heavy" and a pregnant female is sometimes referred to as a gravida. Gravidity refers to the number of times that a female has been pregnant. Similarly, the term parity is used for the number of times that a female carries a pregnancy to a viable stage. Twins and other multiple births are counted as one pregnancy and birth. A woman who has never been pregnant is referred to as a nulligravida. A woman who is (or has been only) pregnant for the first time is referred to as a primigravida, and a woman in subsequent pregnancies as a multigravida or as multiparous. Therefore, during a second pregnancy a woman would be described as gravida 2, para 1 and upon live delivery as gravida 2, para 2. In-progress pregnancies, abortions, miscarriages and/or stillbirths account for parity values being less than the gravida number.