Strange that there were sooo many un-neutered little boys running around unattended.
Look, $100 isn't all that much if it saves her life. What if a 25-30 pound male mated with her? No way she could survive that. You have a responsibility to your Dog to care for it to the best of your ability. This is not an option. You must take her to the vet.
Furthermore, I understand your pro-life stance. I have the same views. But this is a dog not a human. Think of HER life.