Clownfish Breeding Signs?

Hi all
I moved my pair of Black Darwins clownfish to their own reef tank (with a bangaii cardinal as the only other inhabitatant) about a month ago. There is a clay pot in there in which they immediately took to hosting.
 
Tonight while sitting eating dinner watching the tank, both the male and female began cleaning the pot and are still vibrating and shaking all over the pot. I have had them for at least 2.5-3 years now so they are mature. The female also has a vent that looks like a bangaii cardinal vent extending from her belly. Is this the egg papilla or just where the poop comes out? They have been cleaning the pot for a while now. 
 
I am just wondering whether this means breeding is approaching?
 
Fingers crossed they are good signs that breeding is near
 
My occelaris clowns in my other tank have been doing the same. They have been cleaning a piece of clay tile and one of their favourite pieces of rock under their toadstool coral for a while as well. Looks like things have been heating up since I seperated the pairs
 
Thanks Matt

Yes I would say they are good signs. No guarantee but good signs. If the female's ovipositor was down my experience is that they spawn that day.

Thanks Fingers crossed for the best! What does the ovipositor look like?

I bet if you google it you can find pictures of it. In the video of my Darwins if you look close you can see it also.

http://youtu.be/4hjzfvfiVl0

it looks like a little white tube coming out of the belly. She might be a little swollen in the belly as well depending on the size of the clutch she has.

RLTW

180 Gallon Mixed Reef

Then I heard the voice of the Lord saying, "Whom shall I send? And who will go for us?" And I said, "Here am I. Send me!" Isaiah 6:8

Ok thanks guys

ya thats where the eggs come out not poop haha my clowns lay eggs usually two or three days after there poop shoot tube pops out haha they will lay soon so keep watch on them so you can keep track of the days because the b&ws normally hatch on day 8 the night of and all my normal ocellaris hatch on day 7 the night of

Thanks Will try get a video next time I catch them clearing pot. They didn't do it as often today? Really hope they do lay eggs soon because that would be amazing!

Matt, you are welcome to come over and see some of my pairs any time.  Generally I have fish laying every day or two so you will be able to look at quite a number of pairs and see the process as they are coming up to laying.
you have my number.

Cheers Darren
I am in the middle of my final exams at the moment but when I am finished I would love to come have a look at your pairs and see how it all works Will message you closer to the time.
Have you ever tried fostering eggs? e.g. Have you ever sold eggs to another breeder and let them try and hatch the eggs? Or sell the very young fry?
Cheers,
Matt