Hello, I'm Dr. Kara. I have over 20 years of experience as a veterinarian and I'd like to help with your concerns about Connie Fern.
I would be highly suspicious of a pyometra or an infected uterus.
As she has had phantom pregnancies in the past I'm sure that your are aware that milk production can occur without breeding. But a phantom pregnancy should not lead to panting and discomfort. That makes me think that she may have a fever, and an enlarged, infection filled pregnancy.
It is rare that antibiotics alone will successfully treat a uterine infection. The best course of action is to have her spayed. It is a more difficult procedure with an abnormal uterus and she will need longer aftercare, fluids and antibiotics post operatively as well as significant pain medication.
If she is a dog that you wanted to breed you can try using higher powered antibiotics and protaglandins to help stimulate uterine contractions to empty the uterus as long as the cervix is open. But this is not successful most of the time, and she must be bred on her next heat and then spayed after pregnancy and raising the pups because chances of another infection are quite high.
As far as if she can wait until morning if she is still eating and drinking, not vomiting, doesn't have a fever (which usually means the infection has become systemic) then she can probably wait. But if she is vomiting or begins vomiting, has a high fever (more than 39.72C rectally) or a tense painful belly then this may be a true emergency with the possibility of her uterus rupturing which means she should be examined tonight.
Please let me know if you have any further questions.