Are there just two sexes: male and female?

The short answer is no. You may be thinking that there of course is the third gender, that is people with ambiguous genitalia. But there's even more.

Science is now discovering that sex is a spectrum and not a binary.

Actually our bodies possess a combination of physical characteristics typically thought of as “male” or “female”. It's a question of which characteristics are predominant in a person, as people can be born with any chromosomal combination.

Intersex people are more common that we think. It's just that unfortunately, doctors conduct surgery on such infants and decide that they are either male or female.