I understand your concerns. In regard to your question, since you are already 18 years of age, there will be growth of facial hair. Facial hair is a secondary sexual character. Some people start early or much later between 11-20 years. Growing facial hair is associated with wisdom and virility depending on hormonal variation. There are other secondary sexual characteristic changes such as change in voice, development of sexual organs. Here your genes could also be a contributing factor. In addition, your body needs some growth treatments like multivitamins (vitamin A) which stimulate the production of sebum .You can also keep your hair follicles and skin hydrated by eating eggs, meat, cheese, liver, broccoli. You can also take Vitamin c which boosts your immune system and keeps your hair and skin healthy. Don't stress about it. If there is no growth after 1-2 years, then you use minoxidil after consultation with your dermatologist.