Accidental pregancy

Question
Please note that we have a 10 month old English bulldog.  She came in heat about a month or so ago.  She is inside dog but does go outside some during the day.  We had a stray dog come around several times while she was in heat.  We thought we did a good job keeping the dog away but now are not so sure.  We were also under the impression that this breed of dog had to be a/i to get pregnant.  However, her nipples are now enlarged and dropping as if they are starting to fill w/ milk.  No other signs that we can visually see but are very scared.  Since this is 1st time in heat could this really be possible? If so, what should we do?  Thank you.  

Answer
Sorry for the delay, computer problems. Your female can get pregnant, obviously, by any dog. The AI is due to the Bulldog male's inability to breed naturally, nothing to do with the fertility of the female Bulldog.

It sounds like you're going to or may have already had puppies. I hope everything is ok and if she's not had them yet, be prepared for a c-section surgery.  I strongly suggest you have her spayed after this episode.