How soon can I know if my dog is pregnant?

how soon will/can I know if my female dog is pregnant? can dogs exhibit--OR--actually have the same symptoms of apregnant human female? my dog has a heart mumur-I need to know what or which level is the worst---1, 2, or 3?

You need to take your dog to the Vet. I am assuming a vet diagnosed the murmur, wasn't it classified then?
Heart murmurs are classified as (1) innocent, (2) functional, or (3) pathologic.
Hopefully she has 1.
Heart murmurs are common in dogs.
I would have her spayed after she delivers. Pregnancy is stressful. Plus you don't need to let her bring more dogs into an already overcrowded world.

she can run away and you will find her near your house in 5 days(ladies need privacy you now)!it also happened with my dog so I just warned you to beware!