Development of Ova (Female Gametes)

The primary oocytes formed at birth (no more will be made, ever), and start meiosis I and are arrested in Prophase I until puberty, during which time many of the primary oocytes regress. Once puberty starts, ONE primary oocyte, every month, will complete meiosis I, resulting in the formation of a secondary oocyte and a polar body. The secondary oocyte starts meiosis II and again stops, this time at Metaphase II.
During ovulation, the secondary oocyte, which is released into the abdominal cavity before then entering the fallopian tube, will complete meiosis II and form the mature egg (ovum) and another polar body, if and only if there is a sperm available. If there is no sperm available the secondary oocyte will be discharged during menstruation without underoging meiosis II.
The first polar body also divides resulting in 2 more polar bodies. Therefore, at the end of meiosis II, there should be at least 2 and maybe 3 polar bodies (if there is fertilization).
In short, the primary oocyte is at Prophase I until puberty.