What are two ways in which a particle that is too large to fit through the cell membrane can enter the cell?

Facilitated diffusion and active transport

Facilitated diffusion is the movement of large particles (that cannot otherwise move across the cell membrane) from an area of higher concentration to an area of lower concentration with the help of trans-membrane proteins.

Active transport is the movement of molecules across a cell membrane from a region of lower concentration to a region of higher concentration using ATP energy. this may occur with large particles that cannot move across the cell membrane or small ones that can but don't due to the concentration gradient.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.