In a word, you'll be feeling big. The beginning of the third trimester marks the end of the "what a cute baby bump!" period. You're ushering in the "holy cow, what did that woman swallow?" era. The sheer truth of pregnancy is that every woman reaches a point where she doesn't think it's possible for her belly to expand any more … and then it does, with a vengeance! As long as your weight gain is on par with what your doc considers normal, try to embrace your ever-changing physique. Some truly major miracles are happening inside.
All that baby-growing is probably having some adverse effects on your comfort in the form of swollen feet and ankles, heartburn and even leg cramps. Fortunately, most of these ailments are treatable or can be eased. Consult your obstetrician for a list of baby-safe heartburn medications, or cut out problem foods from your diet altogether. Try to avoid being on your feet for long periods of time, and make sure you're getting enough magnesium in your diet to ward off middle-of-the-night leg cramps.