Scientists don't understand as much as they'd like about the female reproductive system, both due to their historical exclusion from studies and the challenge in replicating the complexities of that anatomy. At last, however, there's progress. Researchers have developed an organ on a chip that models a woman's entire reproductive system, including menstruation and hormone-induced responses. It clearly doesn't look like the real thing (see above), but numerous key behaviors are present.
The design revolves around human and mouse organ cells (mice sometimes produce similar results) grown in a network of cubes, each of which has tubes that feed the cells with blood and hormones. There are even pumps and valves to simulate pressure. If you want to replicate a particular condition, it's as simple as injecting the right hormones to produce a reaction from the relevant cells.
To be clear, the current chip model can't account for everything. It doesn't include a placenta (rather important for measuring pregnancy-related effects), for a start. However, it's accurate enough that it could shed new light on how the reproductive cycle works and lead to better solutions. It could test the effectiveness of new birth control methods, model the behavior of cervical diseases or explain why some miscarriages occur. In short: a once nebulous part of human biology is about to become much clearer.