A newborn can have as many as eight to ten bowel movements a day, but as long as she is having at least one, she's probably all right.
One day without a bowel movement is usually no cause for concern. As long as your baby is feeding well and wetting her diaper five or six times a day, then she's most likely getting enough to eat. If she starts to become uncomfortable or has a persistently swollen abdomen, then she may need some help with pooping, and you should speak to your pediatrician about how to facilitate this.
In the early days, a newborn's bowel movements are thick and dark green in color. This is due to a substance called meconium that has been building up in her intestines during pregnancy. As the baby starts to feed and have bowel movements, she will finish expelling the meconium and her stools will start to turn yellowish. It is not uncommon for an infant's bowel movements to vary in color from day to day. The color of the stools can depend on a variety of things, including what a breastfeeding mom is eating, how hydrated the baby is, and the type and frequency of formula the infant is being fed, if applicable.
Source: https://www.babycenter.com/
