I have read your question,
Generally Headache may occur due to various reasons, like sinusitis
, common cold
, viral infection,stress,etc.
So concluding this as migrane
is not neccessary,
Since you said you work on computer for long hours , I think that could be the important thing to note , since concentrating on the screen and staring it for long may also cause headaches
I suggest you to take breaks at works , drink plenty of water , eat low fat and green veggies and practice meditation
and i Assure you it will work.
If you face this problem for more than i week i suggest you to Consult a physician nearby and do tell him your medical history.
Wishing you a good health,