I'm 5'2 and 99lbs. Some say im anorexic but is anything wrong with just being small?

Check standard chart. The proper weight for height can be determined from standard charts. One good source was compiled for kids and young adults & is available at www.Healthychildren.Org thru a search for growth chart. Place your height at the 18yr point on the graph and look at the expected weight for the height on the weight graph below. If you are < 85 % of that weight you would be noticed, <75% possibly anorectic.