Bubbly mouth

[Jrich]

I purchased a beautiful ball python on March 8th from a reptile expo I attended. Before buying her I inspected around her mouth and for mites and she looked healthy. I also had her checked by the vet a few days after purchasing her.
So I've had her for almost a month now and have had a few meals in her, which she has pooped out already but she has refused for the past 2 weeks, which is ok too.
I've been letting her settle in so I haven't disturbed her much lately.
However today I opened her cage to get her out for some pictures and noticed she looked like she was about to shed. That's fine but upon closer inspection she had bubbles coming out of her mouth and she would slowly open and close her mouth with a little bit of squeak. Just great. Also you'll see that there's a dark rusty color smeared around the edge of her mouth. Now I don't know if that's dried blood or if it's stained from the reptibark because I lightly misted in there a few days ago on the reptibark. I really don't want to try rubbing around her mouth or her head right now.
Just a few notes on the enclosure. Hot spot is under tank heater that sits around 90-95 Fahrenheit that is plugged into a thermostat. Cool side is 70-73. Both are monitored by thermometer probes. She's in a plastic tub with many many ventilation holes at the top and a water dish large enough to soak herself.
I'm thinking respiratory infection but I could be wrong. I'm going to call the vet as soon as they open tomorrow to try to get her in. Right now if there's anything I can do for her please let me know or if you have any other information. Thanks all. This really ruined my day.