Here are 10 common surprises that pregnancy can bring.

1. The Nesting Instinct

Many pregnant women feel the nesting instinct, a powerful urge to prepare their home for the baby by cleaning and decorating.

As your due date draws closer, you may find yourself cleaning cupboards or washing walls — things you never would have imagined doing in your ninth month of pregnancy! This desire to prepare your home can be useful — you'll have fewer to-do items after the birth. But be careful not to overdo it.

2. Problems With Concentration

In the first trimester, tiredness and morning sickness can make many women feel worn out and mentally fuzzy. But even well-rested pregnant women may have trouble concentrating and periods of forgetfulness.

Thinking about the baby plays a role, as do hormonal changes. Everything — including work, bills, and doctor visits — may seem less important than the baby and the coming birth. Making lists can help you remember dates and appointments.

3. Mood Swings

Premenstrual syndrome and pregnancy are alike in many ways. Your breasts swell and become tender, your hormones go up and down, and you may feel moody. If you have PMS, you're likely to have more severe mood swings during pregnancy. They can make you go from being happy one minute to feeling like crying the next.

Mood swings are very common during pregnancy. They tend to happen more in the first trimester and toward the end of the third trimester.

Many pregnant women have depression during pregnancy. If you have symptoms such as sleep problems, changes in eating habits, and mood swings for longer than 2 weeks, talk to your health care provider.

4. Bra Size

An increase in breast size is one of the first signs of pregnancy. Breast growth in the first trimester is due to higher levels of the hormones and . That growth in the first trimester might not be the end, either — your breasts can continue to grow throughout your pregnancy!

Your bra size also can be affected by your ribcage. When you're pregnant, your lung capacity increases so you can take in extra oxygen, which may lead to a bigger chest size. You may need to replace your bras several times during your pregnancy.

5. Skin Changes

Do your friends say you have that pregnancy glow? It's one of many effects that can come from hormonal changes and your skin stretching.

Pregnant women have increased blood volume to provide extra blood flow to the uterus and other organs, especially the kidneys. The greater volume brings more blood to the vessels and increases oil gland secretion.

Some women develop brownish patches on their face called melasma (also called chloasma or mask of pregnancy). And some will notice a dark line in the middle of the abdomen, known as the linea nigra (or linea negra). They can also have hyperpigmentation (darkening of the skin) of the nipples, external genitalia, and anal region. That's because pregnancy hormones cause the body to make more pigment.

This increased pigment might not be even, so the darkened skin may appear as splotches of color. It can't be prevented, but wearing sunscreen and avoiding UV light can minimize its effects.

Acne is common during pregnancy because the skin's sebaceous glands make more oil. And moles or freckles that you had before pregnancy may get bigger and darker.

Many pregnant women also get heat rash, caused by dampness and sweating. In general, pregnancy can be an itchy time for a woman. Skin stretching over the abdomen may cause itchiness and flaking. Your doctor can recommend creams to soothe dry or itchy skin.

Most skin changes get better or go away after the baby is born.

6. Hair and Nails

Many women have changes in hair texture and growth during pregnancy. Hormones can make your hair grow faster and fall out less. But these hair changes usually aren't permanent. Many women lose some hair in the postpartum period or after they stop breastfeeding.

Some women find that they grow hair in unwanted places, such as on the face or belly or around the nipples. Changes in hair texture can make hair drier or oilier. Some women even find their hair changing color.

Nails, like hair, can change during pregnancy. Extra hormones can make them grow faster and become stronger. Some women, though, find that their nails split and break more easily during pregnancy. Like the changes in hair, nail changes aren't permanent. If your nails split and tear more easily when you're pregnant, keep them trimmed and avoid the chemicals in nail polish and nail polish remover.

7. Shoe Size

Even though you can't fit into any of your pre-pregnancy clothes, you still have your shoes, right? Maybe — but maybe not. Extra fluid in their pregnant bodies mean that many women have swollen feet. Also, joints tend to be looser during pregnancy. When the extra weight of pregnancy pushes down on loose joints in the feet, the feet get flatter, longer, and wider. Women often need to wear a larger shoe size when pregnant, and sometimes even after pregnancy. Wearing slip-on shoes in a larger size can be more comfortable, especially in the summer months.

8. Joint Mobility

During pregnancy, your body makes the hormone relaxin, which is believed to help prepare the pubic area and the cervix for the birth. Relaxin and other things related to the pregnancy loosen the ligaments in your body, making you less stable and more at risk for injury. It's easy to overstretch or strain yourself, especially the joints in your pelvis, lower back, and knees. When exercising or lifting objects, go slowly and avoid sudden, jerking movements.

9. Varicose Veins, Hemorrhoids, and Constipation

Varicose veins, usually found in the legs and genital area, happen when blood pools in veins enlarged by pregnancy hormones. Varicose veins often go away after pregnancy. To help prevent them:

• avoid standing or sitting for long periods
• wear loose-fitting clothing
• wear support hose
• raise your feet when you sit

Hemorrhoids — varicose veins in the rectum — are common during pregnancy as well. Your blood volume has increased and your uterus puts pressure on your pelvis. So the veins in your rectum may enlarge into grape-like clusters. Hemorrhoids can be very painful, and can bleed, itch, or sting, especially during or after a bowel movement (BM).

Constipation is another common pregnancy woe. It happens because pregnancy hormones slow the passing of food through the gastrointestinal tract. During the later stages of pregnancy, your uterus may push against your large intestine, making it hard for you to have a BM. And constipation can contribute to hemorrhoids because straining to go may enlarge the veins of the rectum.

The best way to deal with constipation and hemorrhoids is to prevent them. Eating a fiber-rich diet, drinking plenty of liquids daily, and exercising regularly can help keep BMs regular. If you are constipated, talk to your doctor about using stool softeners or laxatives. If you have hemorrhoids, ask about a cream or ointment that can shrink them.

10. Things That Come Out of Your Body During Labor

So you've survived the mood swings and the hemorrhoids, and you think your surprises are over. But the day you give birth will probably hold the biggest surprises of all.

During pregnancy, fluid surrounds your baby in the amniotic sac. This sac breaks (or "ruptures") at the start of or during labor — a moment usually referred to as your water breaking. For most women in labor, contractions start before their water breaks. Sometimes the doctor has to rupture the amniotic sac (if the cervix is already dilated).

How much water can you expect? For a full-term baby, there are about 2 to 3 cups of amniotic fluid. Some women may feel an intense urge to pee that leads to a gush of fluid when their water breaks. Others may only feel a trickling down their leg because the baby's head acts like a stopper to prevent most of the fluid from leaking out.

Amniotic fluid is generally sweet-smelling and pale or colorless. It's replaced by your body every 3 hours, so don't be surprised if you continue to leak fluid, about a cup an hour, until delivery.

Other, unexpected things may come out of your body during labor. Some women have nausea and vomiting. Others have diarrhea before or during labor, and passing gas is also common. During the pushing phase of labor, you may lose control of your bladder or bowels.

A birth plan can help communicate your wishes to your health care providers about how to handle these and other aspects of labor and delivery.

Lots of surprises are in store for you when you're pregnant — but none sweeter than the way you'll feel once your newborn is in your arms!