Dear Friend
Headache can be a result of
Sinus infection, that you might be having as you have shivering and
cold.
But , your shivering and cold started 2 days after the procedure you had underwent, a possibility of infection as a procedural complication can't be ruled out.
I need to know, what medications you are taking, as a few medications can also lead to headache.
I also want to know about your headache:
1. Is it on one side of head or both the sides
2. Any throbbing associated with it?
3.Any
photophobia or phonophobia?
4. Any
nausea or vomitings?
5. Any band like sensation or heaviness?
I advise you to consult ypur doctor who has done the procedure you are talking about, and in the meantime, reply with my questions , so that i can help you further.
Stay Healthy