I noticed a small detail when I listened to chapter 20-3 at around the 7:07 mark. Tar described her eyes as being green which is quite odd because if you listen to chapter 2-2 at around the 8:32, you notice that Micheal describes her eyes as being blue. So it seems that there is something wrong here because her eyes are being described as two totally different colors. Also green is what Micheal described the tattooed zombie's eyes to be. Also maybe her vomiting is happening not because she is pregnant, but because she is infected. The vomiting is just a sign of her starting to turn. The pregnancy theory might just be a red harring.