A very good question young man, a condom is part of the male genitalia It will start growing once the penis is fully formed, It varies from person to person but the normal range is 15-18 depending on your genes your condom will be a different color (*the most common being brown*) It will take up to a month to form once this is done you are ready for intercourse. *ADDITIONAL INFORMATION* - If your don't see the start of a condom growing once your 18 you may have genetic disorder in which the condom doesn't form naturally, there is an operation which can be preformed in which the plaster a synthetic condom over the tip of your penis (*you will need to get is changed once a month*). - It isn't rare that an infection might occur while the condom is growing, if this happens contact a doctor immediately before irreversible damage is done. I hope you find this little article helpful :)