Hey Komal!
The current month data is being shown cause your condition it says show everything from the last three months.
If you want to avoid the current month and for example show only the ones older than 2 months, you can try with this
[createdDate> '[%BeginOfCurrentDay%] - 3 * [%MonthLength%]' and createdDate< '[%BeginOfCurrentDay%] - 2 * [%MonthLength%]' ]
Hope this helps you.
Kind regards