The fetus reaches viability (can survive with medical help if born). Lungs are still maturing. Rest if you feel tired.
Period calculator
Week 28 - Rapid Weight Gain
Week 12 - End of First Trimester
Week 9 - Fetal Movement Starts
Stress Relief Techniques
Week 17 - Fat Layers Develop
Implantation calculator
Week 40 - Ready for Birth