The normal menstrual cycle generally works on an average 28-day schedule. If you miss a period, this is a strong indication that you may be pregnant. Other factors that may cause missed periods include:
- change in birth control intake or type
- rapid weight loss or gain
Known as implantation bleeding, this occurs because a fertilized egg implants itself into the endometrial lining of the uterus. This is different than menstruation; it is typically lighter and does not last as long. Color can vary from pink to a dark brownish-red. Implantation bleeding can start as early as nine days after conception. Not all women experience this, but spotting is not uncommon. Sometimes minor cramps accompany the bleeding.
Pregnancy increases the volume of blood in a woman's system. This causes the kidneys to work harder to process waste and water, so more fluid reaches the bladder. Thus the bladder must be emptied more frequently. Also, a woman's growing uterus pushes on the bladder so it has less capacity.
A feeling of heaviness or fullness in the breasts often occurs in the early stages of pregnancy. The areolas also darken in color. Both of these symptoms are due to the changes in hormones during pregnancy—specifically, due to the increase in estrogen production in your body.
A constant feeling of tiredness is common because the body is going through new physical strain. Hormonal changes— specifically, the increase of progesterone production in your body—can also make you feel exhausted.
Nausea is an uneasy or unsettled feeling in your stomach that can lead to vomiting. This feeling—when it occurs during pregnancy—is often referred to as morning sickness though it can happen at any time of day or night. The cause of this nausea is unknown. However, increased hormone levels, stress, and other body changes are probably contributing factors. Morning sickness is common in the first trimester of pregnancy, and with some women it can last throughout the entire pregnancy. Morning sickness tends to be worse for women who are going through their first pregnancies.
Metabolism slows because of hormone changes due to pregnancy, and this can cause bloating. Pregnancy bloating is similar to what a woman experiences during her period.