Your body knows. That why you get constipated. Your diges t I've system slows down to increase absorption. The nausea is due to your hcg levels which is produced by the placenta. You breast enlarged due to hormones released to prepare for nursong. Also do to increased blood flow. Your immune system decreases in order to attempt to carry the baby. If it didn't your body may attack the baby as foreign. Your hips ache from them streching from relaxin which is released to help with widening of the pelvis. Your body knows exactly what it's doing, it's just a bit miserable! :)
??? I'm confused... Your body is the first thing that make changes when your pregnant