I may have a problem on my hands. I have a 100lb male choc-lab and a 15 pound female pug in heat. Both are not fixed and I think my lab tried to give it to the pug. Is there a chance she could get pregnant??
Yes, it is possible they could have bred, and very dangerous to the Pug if they did. The puppies can be to large for her to carry or deliver. I would take this girl to the vet immediatly if you suspect she might be pregnant.
Keeping two unneutered dogs especially of varying sizes like that is foolish to say the least. You need to spay the pug immediately in case she did get bred though I would imagine even the breeding could have injured her terribly and surely you would know, but in any case this will continue to be an on going problem if you don't solve it now..