Lump on back of neck

What was she given the antibiotics for?  The lump could be a sterile abcess if it is near the injection site.  I would be more concerned about the continued bleeding  and lack of appetite.  If she had a UTI I would think she would be better by now.  The antibiotics could be making her nauseated.  Glad she is being checked tomorrow.  Be sure and mention all your concerns when you go back.  I tend to forget all my questions so I write them down before I go, otherwise I have to call back about a million times. LOL  Sorry I can't offer much else but do hope you get some answers tomorrow and she is better soon.

She was given the antibiotic shots because the vet thought that maybe the bleeding was due to a urinary infection

Did the Vet get a urine sample?  They don't need to guess if it's an infection if they check the sample. Call them today and ask if they want you to bring in a sample.

yeah, it's kind of strange that they jumped *right* to an antibiotic injection rather than meds.  Which leads me to think it might have been a very very serious UTI.

Lethargy is *always * a scarey sign, and there really shouldn't be stomach upset if it was a *shot* of antibiotics.  So yes, vet definitely.

Get more information -- I know sometimes it's daunting but ASK:

1.  What were the two antibiotics.  And why TWO?  Why shots not pills?

2.  Make sure they see the lump on the neck -- it sounds like it didin't distribute which could lead to another whole set of problems (which could lead to the dog being a bit septic which could cause the tummy upset).

3.  Did they take a urine sample?  THEY SHOULD HAVE.  They shouldn't have jumped straight to a shot without it.  And now you **need** one -- not just to determine infection but also to do a complete urinalysis to see if there are stones, casts or even just crystals. 

Honestly you should feel easy enough with your vet to call THEM ... call and say "there's a lump where that injection was and she's still not acting well -- what's up?"