Because doctors measure pregnancy from the start of your last menstrual cycle, when you're four weeks pregnant, you may just have missed your first menstrual period. At this point, implantation of the embryo just occurred around one week ago, but already your baby is making his presence felt through hormonal changes. Since your baby is still no bigger than a dot on a piece of paper, he isn't yet causing the physical changes that occur later in pregnancy, but hormonal changes can cause discomfort. Abdominal pain can also indicate potentially serious conditions as well, so notify your doctor.
Typical Causes of Abdominal Discomfort
In early pregnancy, your uterus is still low in your pelvis, far below your waist. Pain around your waist may be related to intestinal changes caused by high levels of progesterone in pregnancy. Progesterone slows the intestinal tract, so constipation and bloating may occur, leading to pain around your waist. You may experience a small amount of cramping and spotting around the time you would normally expect your period as well, according to MayoClinic.com.
Serious Causes of Abdominal Pain
Sometimes serious conditions such as ectopic pregnancy or threatened miscarriage can cause abdominal pain in pregnancy, although ectopic pregnancy more often occurs on either the left or right side of the lower abdomen. Around 1.9 percent of all pregnancies are ectopic, which means they implant outside the uterus, Dr. Anne-Marie Lozeau reports in the November 2005 issue of "American Family Physician." Around 97 percent implant in the fallopian tube, but around 3 percent implant in the ovary, abdomen or cervix, according to Lozeau. If you continue to have pain, notify your doctor. The fallopian tube could rupture, causing life-threatening bleeding. If you have an ectopic pregnancy diagnosed early, you may be able to take medication rather than undergo surgery.
Pregnancy can aggravate sciatic pain from the nerve that runs down the buttock and leg, although only 1 percent of pregnant women experience sciatic pain during pregnancy, according to BabyCentre UK. More often, the hormone relaxin softens the ligaments in the leg, which relaxes the joints so your pelvis can expand. This process can put pressure on other ligaments and muscles, causing pain down your buttocks or leg. Your legs may also feel weak. Fluid retention can also cause your legs to feel heavy. Leg cramps, also common in pregnancy, and varicose veins generally don't cause problems until the second trimester of pregnancy, although some women experience them earlier.
When you're pregnant, you experience a number of minor complaints that can scare you into thinking there's something wrong with the pregnancy. While most pregnancy complaints do not have a serious cause, check with your doctor whenever you're concerned that your symptoms indicate a problem. Do not take over-the-counter pain medications to treat discomforts without talking to your doctor first, since aspirin and ibuprofen generally are not recommended for use in pregnancy, obstetrician Dr. Roger Harms says on MayoClinic.com. Your doctor may approve occasional Tylenol use for the normal aches and pains of pregnancy.