GA Goal Conversion - number doesn't tally
I have a question pertaining to Goal Conversion. My question is, does it include the post click conversion, i.e. people landed on the website but didnt convert immediately.
Some context bin case you want to understand more:
We are running a digital campaign (not with adwords) for a client, what we have done in order to do conversion attribution modelling is the following:
(1) In GA, we set up Goal Conversion
(2) We have UTM URL implemented so that we can identify in overall which are the best performing platforms and strategy, and to isolate to paid media & organic source
The campaign period is 07 Oct - 31 Jan, and in the mid of the campaign 21 Dec, we implement a new strategy. And to find out if the strategy work we are isolating the conversion number based on the following:
(1) 07 Oct - 20 Dec (the goal conversion from Source A is 69)
(2) 21 Dec - 11 Jan (the goal conversion from Source A is 104)
But what i get from the overall campaign period from 07 Oct - 11 Jan is 175 (from Source A & Source B & C), of which only 79% of the conversion is from Source A.
Can anybody tell me if i missed any step/ things when i run the report?
Thank you very much!