Can u plse let me no if must one sit for 40days after giving birth,Is there any specific duas or Kitaab that i can buy for duas to read on pregnancy or wot must or musnt be done when pregnant

There is no Iddat (waiting period) after birth like in divorce and death.

However, the maximum period of Nifaas (bleeding after birth) is 40 days. It
is not necessary for a woman after birth to sit for 40 days in the confines
of her home. However, she should take care of her health after birth.

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai