On AWS, I already have an EC2 instance and PostgreSQL RDS which is working fine for more than 2 years. Now I added new EC2 instance and a new PostgreSQL RDS ( both are under free tier ). Later I found that the billing is added to this RDS even though I have selected free tier. Is this possible to create another EC2 and another RDS in the Free Tier when there is a EC2 and RDS running more than 2 years?