Yes, it is true that during the early stages of human development in the womb, the reproductive system begins with a common structure that has the potential to develop into either male or female reproductive organs. In the absence of specific hormonal influences, this early reproductive system follows a female pathway.
Around the fifth or sixth week of gestation, the presence of the Y chromosome in male embryos initiates the development of male characteristics. The Y chromosome contains a gene called SRY (Sex-determining Region Y), which triggers the release of hormones that lead to the development of male reproductive organs, such as the testes and the penis.
If the embryo does not receive the genetic signal from the Y chromosome, it will continue to develop along the default female pathway. Female reproductive organs, such as the ovaries, fallopian tubes, and uterus, will form in the absence of specific male development.
So, in a sense, all embryos follow a similar developmental path initially, which can be considered "female" in the absence of certain genetic triggers. However, it's important to note that this is a simplified explanation, and the intricacies of sexual development involve various biological processes and genetic factors.