I understand that your question first went to Vet only experts who chose for whatever reason not to answer your question. At around 9:50pm it was dual categorized to open it up to non vet animal experts whose credentials have been verified. At that point, I saw your question and reached out to get in touch with you.
Since you already waited so long, I don't want you to have to wait after you respond, so I'm going to give you some possibilities.
Most dogs during the second month of pregnancy experience a mucousy discharge which is not always noticeable though it seems to be seen most often after a dog urinates. I usually notice this discharge in my females closer to the 6th week of pregnancy. Dogs are pregnant about 63 days from the FIRST mating. So if you are seeing a mucousy discharge that would be pretty normal.
Another possibility would be fluid leaking from the anal glands. Dogs that are pregnant usually develop parasites. Parasites tend to lay eggs
that lay dormant in the intestines until the hormone shifts associated with pregnancy triggers them to hatch. These parasites can lead to loose bowels and then to anal glands that may not be expressed naturally on the firm fecal matter. In some dogs, they will leak the fluid if not self expressing on the feces.
Another possible cause would be incontinence or a leaky bladder. Some dogs develop incontinence as the puppies press on the bladder more. In other cases a urinary tract infection might cause accidents.
Urine obviously smells a particular way and anal gland fluid can range from near odorless to fecal in nature and is usually foul smelling. Normal vaginal discharge is pretty much odorless. Now a dog can develop a uterine infection and have a discharge that is a clear fluid or a bloody discharge. That would be pyometra and is seen usually 60-90 days after a heat cycle
. This usually strikes older females but can strike any age. Usually with pyometra, you will see vomiting and diarrhea as well. Let me give you a site on this so you have the information if it does end up being the early stages of an infection.
Usually when you witness a female achieve a tie (stuck together) with a male, pregnancy does result. However, if you haven't had an ultrasound or other pregnancy testing done, she may not be pregnant. Usually the earliest you can be sure with testing is about 21 days post mating. If you haven't had any imaging done and the discharge is not a little mucousy discharge seen after urination, then you might want to have your vet take a quick look and ensure there is no uterine infection or urinary infection present.
Again, I am sorry that no vet chose to answer your question sooner and hope you do not hold that site issue against me. I have been breeding professionally for over 18 years and also worked as a vet assistant for many years so I do have a lot of experience with pregnant dogs and the health issues they experience.
I hope this information is helpful to you. If you need more information or clarification, please reply and I'll get back to you as soon as possible. If you are satisfied, please take the opportunity to rate.