How are you determining your ovulation? If your period isn't due for 2 weeks, then that means you are ovulating now or yesterday and there is no possibility of being pregnant right now. You would have to of ovulated on CD 10 at the latest to experience implantation spotting on CD 17. You should get your period 12 to 15 days after you ovulate if you are not pregnant. If you ovulate before CD 10 or even on CD10, there is a chance the follicle is not mature and there is also a chance your lining will not be thick enough to allow implantation. If you do ovulate early in your follicular phase and have a healthy luteal phase, you will have a 24 to 25 day cycle. If that is the case, your period is due today or tomorrow and not in 2 weeks.
I would ask for medicated cycles with ultrasounds to induce ovulation when the follicle is mature. You will know exactly when you ovulate and this will greatly increase your chance at pregnancy since PCOS can prevent ovulation.
You might want to discuss taking progesterone 2 days after you ovulate to ensure your hormones are balanced. Depleted progesterone causes breakthrough bleeding.