my bitch was mated on 2nd april,  on the 4 th and 6th she was given the morning after injection and i was asured by my vet that she would become in season again,  she finished her season and then a whitish fluid appeared from her back end,  now nearly 6 weeks on her nipples have dropped and there is a fluid from the back 4, shes definetly heavier but with it possibly being her first litter i cant feel anything, what is the likely hood of the injection failing? or is it a false pregnancy? shes eating fine, not clingy to any toys or the like and generally just more laid back.  if it is a false pregnancy when will it be over? the vet said i could opt for a 3rd jag but in most cases its not needed and hes never had a pregnancy after giving the jag but could it be his first?
any advice welcomed

Your best bet is to take her to the vet to be scanned. Then you'll know for sure what you're dealing with.