Can A Female Dog Be Pregnant By Two Male Dogs At The Same Time?

I would have to disagree with the last comment.  I learned that its is possible for a dog to be pregnant by multiple males...if time allows.  Its has to be within a certain time frame for this to happen.  Also it is very possible for a human to do the same.

Yes. A female in season can tie and take several times during her season. There can be more than one sire to her litter and then you have a big mess doing DNA testing to match which pup to which sires since you can't say it's one dog and have it be the other.
It's also the reason for many runts and why they often catch up to the others. If the female has her pups on day 60 from the first tie but some were conceived during later ties they will be at a different stage in development when the birth occurs (and sometimes don't make it depending on how far apart and how premature they actually are). Breeding is complicated.

Yes mine did

OH My, what a brilliant question? And just to think if mammals could become pregnant after already being pregnant, two men, or two dogs one baby two daddy's......the best to you.....