This diagram shows the menstrual cycle. Explain whether the
female is pregnant.

Please explain why because I’m struggling.

According to the hormone diagram of the menstrual cycle, the woman is not pregnant due to the behavior of progesterone and estrogens, whose levels do not increase, in addition to the absence of human chorionic gonadotropin.

Explanation:

The graph shows the behavior of hormones during a woman's menstrual cycle in the absence of pregnancy.

During a woman's normal cycle, estrogen, luteinizing hormone (LH) and follicle stimulating hormone (FSH) tend to increase prior to ovulation, reach their peak values at ovulation, and then decline, as shown in the graph. Progesterone, on the other hand, increases after ovulation and decreases if the woman does not become pregnant.

In the case of a pregnant woman:

The diagram represents the normal cycle of a woman who is not pregnant.

your spelling is a little off : ]