Yes. It only takes about 2 weeks for the pregnancy hormones to leave your body during which time 66% of postpartum women will experience "baby blues." a minority of these women will go on to have postpartum depression. Risk factors include prior history of depression, baby admitted to nicu.
Hopefully. Many emotions can be attributed to hormonal changes during pregnancy, so as those hormones return to normal, your emotions should slowly get better. Pregnancy itself, and having a baby can be very emotional and stressful too, which is not uncommon. If you still feel stressed and emotional, discuss with your dr. As their is help available. Good luck.