If she is over 58 days pregnant then leaking of fluid can be sign that she is going to deliver puppies very soon but if she is below 58 days pregnant then any vaginal discharge is not normal and requires vet visit. If your dog is pregnant and approaching towards end of gestation then note following signs.
- Reduction in rectal temperature below 100o F
- Restlessness and pacing
- Loss of appetite
- Nesting behavior