WELCOME SnowflakeSara831!! What a wonderful heart you have!
Don't panic, most likely what you are seeing is a harmless pigmentation due to diet or the season. Actual blood is rare, but red urine is actually not uncommon. Check out this article http://www.rabbit.org/journal/3-1/r...urine.html
Is she eating and pooping normally? What was her diet previously, and what is her diet now? How old is she? Has she been spayed? You said that he never gave her anything to help wear her teeth down? Is she suffering from any malloclusions?
If you truly feel it is blood, then she should be seen by a vet as that can be sign of cancer.
Vets, no matter what the animal, are expensive! (but especailly with rabbits because they actually are in the "exotic" category with vets) And one thing with rabbits is that they can get sick and die within 24 hours, and waiting can be a matter of life or death with rabbits, so being able to run to the vet is important. I have a tip that can help with having to deal with last minute expensive emergencies that may happen in the future. I have pet insurance! The one I use is www.petinsurance.com It cost about 12 bucks a month, and they pay about 70% - 80%, and they pay claim usuallly in a couple of weeks. The only thing they don't cover is parasitic problems and pre-existing conditions.
I know I sound like a sales ad. I don't work for them, don't get commission, or any kind of compensation for referring. I just have been singing their praises because they have personally saved me over $1000 when one of my bunnies got a serious abscess. The surgery was $900, the meds, the follow ups etc. was ridiculous. I also got a credit card just to cover emergencies, and so I could pay up front, and then by the time the cc bill was due, I was getting paid by the insurance company.
Again WELCOME! and keep us updated! I am so happy you got that bunny away from her situation and taking care of her. A big heart! Bunnies come with all kinds of challenges - littertraining, house proofing, etc. We're here to help you out!