By now, your wife’s body has changed significantly. Some changes, even as a non-girl, you expected, like her expanding belly. You may have been surprised to see a faint line, called the linea alba or negra, that goes from her navel to the top of her pubic bone. The darkening is caused by increases in estrogen and progesterone, which in turn step up production of the pigment melanin, a condition known as hyperpigmentation.
Here’s an old wives’ tale your wife might not know: if the linea negra runs just to the belly button, you will have a girl; all the way up to the ribcage, and it’s a boy. Don’t paint the baby’s room based on that data, however.
Your wife’s breasts will also have grown significantly, and will likely appear more inviting to you. While her breasts were probably the most sensitive early on the pregnancy, the increased fullness is sometimes accompanied by increased sensitivity and your amorous squeezes may be met with squeals of pain.
Your best bet here is to talk to her about what she is feeling while reassuring her of her continued attractiveness. There is no “normal” when it comes to sexual desire in the last trimester. If you’re lucky, she is feeling more sexy than ever given the absence of birth control and her more erotic, curvy shape. On the other hand, she may be feeling more uncomfortable and body-conscious, especially this late in the pregnancy.