Well, if you're not going through puberty, then it makes perfect sense that your penis would not have started to grow yet. You penis and testes will not start to enlarge until puberty starts. You're 14. It is normal for many boys not to reach puberty by 14, but it should come soon. Are you starting to grow body hair (pubic, armpit, face) and has your voice started to change yet? You might want to watch for those signs first to figure out how your development is progressing. If you have not started puberty by age 16, definitely speak with your doctor.
Till then, please read the following articles: