We have a white labrador retreiver.   SHe is 12 months (9/23/05).  We noticed on a Tuesday that she began to swell.  Noticed a slight trickle of blood on Saturday.   Did not notice any more blood or any discharge.  She got out of her pen on the next Wednesday.  She and the male (yellow lab - 3 years old) were found "stuck" together.  They released a few moments later.  I do not know how long she was out of the pen from 7a - 6p. Therefore, what are the chances that she is pregnant?  How many mating times does it take to become pregnant?  How much discharge should there be?

I will be taking her to the vet in early am.   Is there anything that can be done to stop this pregnancy.

Yes she probably would be pregnant, as in humans it only takes the once, and hte conception rate is better in canines than humans.

A form of morning after injection can be given to terminate a pregnancy.  The safest and surest method is to arrange to have her spayed in the next few weeks.