You need to put up the matter of pregnancy to the company in writing.
Are you covered by ESIC?
Inform the company that I do not want to quit and your previous resignation was under pressure.
If still they do not relent, go the Labour officer of the area and complain regarding your problem.
There are statutory rights granted as welfare entitlement to women employees and employers who try to deny them can be taken to task by concerned govt agencies.
14th May 2019 From India, Pune