Breastfeeding can make you get a negative pregnancy test even when pregnant ??

This woman just told how she kept testing and kept testing Becca of symptoms and the pregnancy tests were all negative. She continued on with her life and breastfeeding dismissing her absent period as a side affect from breastfeeding because it can cause irregular cycles. One day she feels MOVEMENT inside her belly. She goes to the doctor and is 22 weeks pregnant. Excuse me??? I’m still nursing my 12 month old and now I’m over here scared to death.