What is up with this cough?

Last week on Sunday night I was recovering from a small cold I had had for only a couple days. That night I developed a semi-dry cough that continued for 4 or 5 days. On the 4th day it became a completely dry cough that was giving me headaches. Thankfully the cough recessed a little and was as severe. This happened on Friday. It is now Tuesday night and I still have the cough but it is getting better at least I think. I want to know what it is I had or still have. I am a 15 year old male and I do not smoke. Also, in the morning when I get out of bed my cough is not dry but gradually dries out as the day proceeds. I don't take any medication and haven't taken anything for the cough. I have only been drinking lots of tea and getting sleep. Please let me know what you think.