Still Uncertain About Pregnancy

Question
My English Bulldog is a little over a year and a half and had her first heat from late December to early January. In the latter half of that time, we went out of the house for the day, and returned to find a hole under the fence in our backyard and our dog with some kind of mark on her muzzle. We suspected a male dog in the neighborhood, most likely an American Cocker Spaniel or Chihuahua, might have snuck in and mated with her within the duration of that outing.
She's now approximately 53 days pregnant, and while her mammary glands are significantly swollen, it's otherwise hard to discern if she is pregnant or not. I've heard random suggestions online, regarding bulldogs simply not showing often or small litter sizes- even that puppies can "shift" late in the pregnancy- but if you have any pertinent information to this situation, I would be extremely grateful.

Answer
Brooke,

I suggest you see a vet.  If she is bred by a small dog, she would probably be able to have the puppies, but if you don't know how to help (get the puppies out of the sac), you could lose the litter.

A vet should be able do to an ultrasound.  Many times a bulldog won't show.  If she has swollen mammary glands that is a good sign that she is bred.

The vet can give you advise about helping when she goes into labor.  Most bulldog breeders have a c-sect done.  You should talk to your vet about that too.  But again, if she is bred by a small dog, that might not be necessary.  

Christine Puetz