I mated my bitch on Friday, lovely mating.  Yesterday she was a little slower eating her breakfast - she is normally very greedy, its gone in seconds.  This morning, she was slow, even taking her head out of the bowl for a minute - unheard of normally.

A good sign?

Haha I'm in the same position - my bitch was mated (but only 2 slips) 8 days ago. I'm sure she has finished her season earlier than usual.....

To be honest I think all the signs we think of as positive we notice after a mating as we are looking for them.

I have mated my youngest champion girl, and she has missed after mating on both the last two seasons, and the next will be last time I try (she has had two litters previously) and I would say she showed all the usual signs but we got no pups.

With a maiden bitch I'd not expect to see much in the way of change of shape until 6 weeks after mating, even longer with fit broad bodied bitches.

A vet good at palpation will tell you at 28 days after mating, no later, as after that fluid stops them being able to feel.  Scans will pick up pregnancy quite reliably after 28  days.

I was watching like a hawk.
I noticed a slight refusal of food too, literally the first time EVER.
Also her expression always keen and focused and sharp, this sounds daft but it softened so much and she became a cuddle bunny.
I did think if not in whelp I might award her an Oscar :)

Around three weeks, mostly nipple changes and attitude.

My friend is also my vet.
She popped around to vaccinate a litter for me and have lunch, natter etc.
I casually asked..about another bitch...." Oh I mated her do you think she's pregnant?"
When I got my statement there was "Palpation to determine pregnancy" itemised on my bill.

I refused to pay of course...cheeky beggar!

Knowing what the undersides of my bitches look like, I find that on day 21 the nipples take on a brighter hue and look quite rosy.

In fact I always make a note of day 21 so that I don't forget.

Not soon enough LOL
Last time I did think I knew but this time no clues so far. She was still flagging quite a few days after the mating and so I started to think I mated too early. Who knows but these few weeks are the waiting and wondering time. I also think with a first litter the nipples are a good indicator as they go from incy wincy to a more obvious pointed nipple. With a bitch and a 2nd litter I don't think it is so obvious.

> She was still flagging quite a few days after the mating and so I started to think I mated too early.

I never take that as an indicator.  I have a bitch that flags from day 3 and throughout the season.  A proper trollop, she would flag for a camel.  Most of my bitches flag for each other so my only guaranteed indicator is asking my own stud dog who never gets it wrong.  Poor boy, he tells me when they're ready and I just take her to my chosen stud.

It's easy to read certain signs wrongly!!    If you are close to your animals however, it is possible to get a 'feeling' pretty early on - and with mine, often the fact their vulva doesn't go back to normal tells me a pregnancy is probably starting.  And some bitches will definitely be seen to take more care of themselves, not rough-housing with the others, pretty early on.  However, I don't normally see anything to confirm or otherwise until after the fourth week by which time there is often a slight thickening of the flanks. 

I would just add that even if she's showing every sign early on, this doesn't mean she won't reabsorb her litter   Also most of mine would appear to have little to no discharge through the final week after being mated - BUT to confound that, I had one who had an increased blood-coloured discharge through her final week...... to the point I thought she's never taken.   She had an uneventful pregnancy and 9 super puppies (so good we kept 3)!

When I got my statement there was "Palpation to determine pregnancy" itemised on my bill.

For sure, that's well cheeky!!!