Why It Happens: Many women feel something akin to menstrual cramps very early in pregnancy. (They often think their period is coming.) That achy heaviness is caused by increased blood flow to the uterus and other pelvic organs, and it's normal.
When To Call The Doctor: If you notice consistent cramping on only one side or if it's accompanied by bleeding (your doctor will need to rule out an ectopic pregnancy or ovarian cyst). Serious cramping in the second or third trimester is more worrisome, as it could indicate early labor.
Why It Happens: Hormonal changes cause pregnant women to retain excess fluid in their tissues; in addition, blood volume increases by 30 to 50 percent. Unfortunately, there's not much you can do about the puffiness.
"It has nothing to do with how much or how little water or salt you ingest," says OB-GYN Richard Frieder, M.D., a clinical professor at the University of California, Los Angeles School of Medicine. If your legs and feet are swollen, elevating them will help; so will swimming. Even sitting in a pool up to your chin will help redistribute the fluids in your body.
When To Call The Doctor: If sudden swelling is accompanied by a headache, especially after week 28; this may be a sign of preeclampsia, a dangerous high blood pressure condition.
Why It Happens: Your cervix is undergoing many changes that can result in unusual or excessive mucus discharge, says Daniel Landers, M.D.
When To Call The Doctor: If your vaginal discharge is accompanied by burning, itching or a foul smell; you could have an infection.
Why It Happens: When a pregnant woman sees a wet spot on her sheets or underpants, she thinks, "My water has broken!" But more likely, the moisture is only urine. Because the growing uterus puts pressure on the bladder, many women leak urine without realizing it.
When To Call The Doctor: If the wetness persists or seems excessive; your doctor will want to be sure you're not leaking amniotic fluid, which is a concern before the 37th week because such leakage could trigger labor or lead to infection in the uterus.
Besides her bleeding scare, Schuler admits she had other worries during her three pregnancies, including chronic vomiting with one and what she perceived as lack of movement in utero with two. "Now that I've had three perfectly healthy babies," she says, "I look back and realize I could have worried a lot less."