Some weeks after the start, I get busy (2,3,2)
I believe the answer is:
on the go
'busy' is the definition.
('on the go' can be similar in meaning to 'busy')
'some weeks after the start i' is the wordplay.
'some weeks' becomes 'month'.
'after the start' means to remove the first letter.
'i' becomes 'ego' (I've seen this before).
'month' with its initial letter taken away is 'onth'.
'onth'+'ego'='ON THE GO'
'get' acts as a link.
(Other definitions for on the go that I've seen before include "ready to start monopoly?" , "Ever busy" , "Busily active" , "Active and energetic" , "Running around busily" .)