Metestrus is a stage in the reproductive cycle of female mammals, occurring after estrus, or heat. During this phase, the body prepares for potential pregnancy. If fertilization does not occur, the body will gradually return to its normal state. In metestrus, the ovaries produce hormones like progesterone, which helps maintain the uterine lining. This phase typically lasts for several days to weeks, depending on the species. If pregnancy does not happen, the female will enter diestrus, the next stage in the reproductive cycle.