Yes, dogs are in heat when they're bleeding, and that is when she will pregnant. If you don't want her to get pregnant keep her away from all male dogs for the entire time she's in heat, including when she's bleeding.
Most certainly your dog can get pregnant is she is still bleeding. In case you don't know this is known as "in heat". This is actually the only time your dog can get pregnant. Rarely a female will go right out of heat but most bleed for a week or so.
If your dog is still bleeding that means that she is in heat. This is how they attract other dogs through the smell as they blood blood from their vagina. You dog is most fertile at this point in time and much more likely to become pregnant if she does have sex.
Not medical Advice: A heat last 3 weeks. The first week is pink to red and tappers off. It is in the third week that the bitches blood thins in color almost to a light pink this is usually when the female is ready to breed.