What examples in chapter 2 of Salvage the Bones foreshadow Esch's pregnancy?

At the beginning of chapter 2 in Jesmyn Ward's Salvage the Bones, Skeetah, Esch's brother, is building a kennel for his dog China's puppies, which were born the day before. He shows the litter to Esch, who think that the puppies look like chicks now that their coats have started to grow. This is the first instance of foreshadowing during the course of the chapter, in which Esch thinks about pregnancy, birth, and caring for young children.

It is while she is hunting for eggs, the ultimate symbol of new life, that Esch finds herself thinking about sex. She recalls losing her virginity at the age of twelve to Skeetah's best friend, Marquise, and then thinks of the other boys she has been with since then. When she has cooked the eggs, she gives them to Skeetah, who in turn gives them to China. China is nursing the puppies and her nipples are swollen, a sight which makes Esch feel sick. When she throws up, Skeetah tries to soothe her by rubbing her back in the same way that he comforts China, strengthening the connection between the two.

Later, on the drive home from the grocery store, Esch makes this connection explicit. Thinking of how she watched China give birth, she wonders if she could be pregnant herself. She reflects that she has missed two periods, often throws up, and has a heavy feeling in her stomach. Although she is briefly distracted by the terrible scene of the car accident, as soon as she is back at home, Esch takes the pregnancy test and finds that it is positive. She thinks in despair of the "terrible truth" which has been foreshadowed in her thoughts throughout the chapter and is now confirmed.

How does Esch perceive her pregnancy in Chapter 3 of Salvage the Bones?

In Chapter 3 of Salvage the Bones, Esch does not have fond thoughts of her pregnancy.  She wakes up each day with morning sickness and spends considerable time in the bathroom vomiting.  She is young, so she hides her pregnancy from her family members (who are all male).  Interestingly, Esch's pregnancy in this chapter is juxtaposed with China the dog's recent birth--later in the chapter, China refuses to feed one of her pups, and Skeetah says that China must know that something is wrong with the puppy.  Esch is also feeling that her pregnancy is "wrong"--Manny does not care for her (let alone love her) and shows her no signs of affection.  He just wants her for sex.  Esch begins to feel bitter towards this situation, and her thoughts about Manny negatively color her thoughts about her pregnancy.