My bitch was mated 13 days ago on day 12 of her season.
20th, 21th and 23rd days of her season I noticed that her discharge has returned to blood/Light blood and 
23th & 24th(today) days she discharge Milky/light creamy colour discharge. she is well and eating etc.  Her vulva is slightly swollen.
The discharge is no smell.  is this normal? is this good sign for pregnant?

It is normal but all my bitches have had creamy/opaque or even yellow discharge after their seasons whether pregnant or not.

Good luck

Most of mine, whether mated or not, just stayed at a pale slightly coloured discharge through the final week, which gradually became less and less until around day 21, that was it.

However, with one I'd had mated, during her third week she went back to a blood-coloured discharge at which point, much as she was otherwise well, I thought she'd never taken.   As it happened, after an uncomplicated pregnancy, she produced (well C.Section!) 9 lovely puppies, 3 of which we kept - they were that good.   All three were among those we brought back to the UK with us and we showed the 2 bitches, one taking a UK title.   Her sister, always overshadowed by her sister, did enough to be perm. qualified for Crufts.    The brother's mouth went edge to edge by the time he came out of quarantine at 18 months (this was before Pet Passport) so I only showed him a couple of times, at Open show level to see whether his bite would be accepted - sadly not.   But I allowed a fellow breeder to use him, with the knowledge that his bite wasn't right - again she was so happy with the result that she came back for a repeat mating.  He is back of a lot of his breed in the UK now.   In fact the buy-in hound we have now, goes back to him.

If your bitch has a discharge beyond her normal season time, I think I'd be slightly concerned (pyometra?).

MamaBas -tnks for your info .

bucksmum - tnks for ur info.