For many women anxious to find out if they are pregnant, waiting until a positive pregnancy test is possible is just unbearable. Although many signs of pregnancy do not appear until weeks after conception, there are a few signs that can occur as soon as a week after conception in some women. Although it is important to realize that not all women will experience these signs at all, let alone as soon as a week after conception, those that do those may have an earlier indication of whether or not they are pregnant.
When a fertilized egg attaches to the uterine lining, a small amount of blood is sometimes shed. This implantation bleeding occurs about one week after conception and is the earliest sign that a woman is pregnant, says the American Pregnancy Association. The bleeding typically is very light and will only last a day or two. It may be red, brown or pink in color and slight cramping may also occur.
As soon as the fertilized egg implants into the wall of the uterus, pregnancy hormones are produced. These hormone surges can cause feelings of extreme tiredness or fatigue, explains the Mayo Clinic. In addition, low blood sugar, low blood pressure and increased blood production also occur in early pregnancy and also may cause feelings of fatigue.
Increased blood circulation and hormone surges created by the fertilized egg implanting into the wall of the uterus can also cause headaches in many women, according to the Mayo Clinic. Although these headaches may continue throughout the pregnancy, many occur during early pregnancy.
The Mayo Clinic states that changes in a pregnant woman's breasts can take place as soon as a week after conception. These changes may include the breasts becoming larger, swollen, tingly or tender. The nipples of the breast may also undergo changes, such as becoming more erect, larger and darker, but these changes may not take place until later on in the pregnancy.