Should I worry about headaches 1 week post lipo?

Headaches after any major surgery are typical unless they are associated with difficulty speaking, differential arm strength or visual disturbances in which case you shoul consider calling 911.
There are many different reasons for this and you should certainly discuss with your physician but some of the more common reasons I encounter are:
1) caffeine withdrawal
2) fluid status fluctuations
3) drug interactions or withdrawal

I am not sure there is a correlation there except that you may be dehydrated from the surgery.  I would hydrate with gatorade and electrolyte rich fluid.  If it does continue on you may want to see your doctor to make sure that nothing else is wrong.
 
Good luck.