Do you clear your throat a lot?
Do you tend to have this coughing attacks more often in the early morning as well as evenings?
If you are clearing your throat a lot, it is most likely one of two things.
You could be having silent reflux, where the heartburn silently and painlessly refluxes up, burning your lower throat, and causing the dry tickle and cough as well as throat clearing. This can be treated with anti-reflux medicine.
You may also have postnasal drip. Again, it causes the same symptoms. There could be a new allergen in the environment which you are not aware you are allergic too, or also if you had a recent cold, postnasal drip can occur afterwards. This can be easily treated with a steroid nasal spray such as Flonase.
I would put my money on one of these two diagnoses,
I hope this helps,