If the flower got pollinated. it will die and fall off. then the whats left is the seed pod. You will know within 1-3 days if it took. it will either die and fall off or the little thing where the flower was will begin to get bigger. it will continue to grow for 8-12 weeks and will get about the size of the tip of your thumb. When it starts to turn brown is when you take it off the plant and your seeds are ready to be planted. You can store the seeds or plant immediately. I have seeds that are 2 years old and still germinate.

I have seeds that are 10 years old and still germinate. Maybe I am just lucky.