Not taking a pig to a vet because the symptoms "aren't bad enough" is a good way to lose a pig. They can go from first symptom to dead in 24 hours. They're prey animals, and as such, symptoms of illness are hidden until they're actually pretty sick.
They're completely dependent on humans for their care, and medical care is just as much a part of responsible pet ownership as food and housing. It's not fair to the animal to have it and not take care of its medical needs.
Maybe you can arrange a loan from your parents, or use your own money for the vet. They need an exotic vet, not a small animal vet. Those treat cats and dogs, and are not educated/trained in the care of exotic pets.