An experienced vet can usually palpate a bitch at about 28 days. The pups will feel like little walnuts.

Somewhere around 32 days she might develop a vaginal discharge. It would be clear/white with no smell at all. If she should have a coloured or offensive smelling discharge she should be seen by the vet ASAP.

According to the dates you've provided, if she came into heat on the 14th she wouldn't normally have been breedable until the 21st. In that case she wouldn't be expected to be showing at the time of your first post on this subject.

But the majority of my experience is with much bigger dogs! It's possible that smaller dogs might start to show their pregnancies sooner.