I am pregnant and can no longer pray while standing and prostrating. Wanted to ask if there is specific rules and guidelines to when I'm praying while sitting on the floor?

I pray with my legs crossed and bend for sujood as much as i possibly can. But do I need to lift the turbah to my forehead?

Recite the namaz while standing and to the extent possible go to rukuu. Then sit on a chair and keep a table in front of you for as low as is possible for you and do sujood on there. Takbiratul ihram and the qiyam before rukuu are rukn of prayers and must be done while standing.