Baby: Week 13
Your liver and pancreas are secreting fluids, and your bones are hardening
You weigh about 70g, and measure 9.1cm long, crown to rump. All your joints and limbs can move, and your legs are finally longer than your arms.
Did you know your first case of hiccups was at 15 weeks? This was your way of practicing breathing! 
What else is going on this week? The liver and pancreas are secreting fluids, and your bones are hardening. You’re growing rapidly, but not without attending to details: even the scalp hair pattern is forming.
BabyCentre discusses week 15 of pregnancyfind out more
University of Maryland Medical Encyclopediafind out more
Mayo Clinic discusses week 13 in pregnancyfind out more