Seeking advice!

My 11-year-old female cat has been using the litter box excessively these last couple of days. I noticed that there was a slight pinkish tint in her urine. Should I take her to the vet as soon as possible, or should I just wait it out? She has used the litter box excessively before, but I haven't noticed the pink until now. Taking her to the vet wouldn't hurt, and it might even benefit her, but it would hurt me financially. I care about my cat's health; I just do not want to spend money I do not have if it is something that will go away on its own. Thank you for your advice in advance. :)