
Sorry, had busy weekend, just seen this. Louise's advice is excellent - she had a pretty bad time with her litter last year :( The Northern Club show is on 3rd November so would be a good chance to see pugs en masse, as would Midland Counties.
Generally, the liklehood of having bought a dog and bitch with little breed knowledge and finding them compatible enough to breed from is low. Just being unrelated does not make them suitable, but carrying along with this point has a look at Mateselect on the KC website, you can get the inbreeding Coefficient by entering the names, I have seen lots of pugs advertised recently state "Mum is from London, Dad is from Birmingham" (or similar) as if distance between the pug parents guaranteed them being none related!
As said before, if you want to share with us why you want a litter, why you think your pugs will be suitable to breed from, how old they are, then more exact advice can be given. What area do you live? Perhaps we can suggest a breeder/pug expert you could visit who can give you an worthwhile evaluation of your boy and girl as a starting point.