I've found the answer myself, so I'll share it with everyone so they can find it too.
When can I start tracking what happens after my NOA2 from the USCIS?
If you've been following the I-129F petition on the USCIS Case Status tracker, then you will notice after the NOA2 is issued it doesn't really give you any more information. As soon as they NOA2 has been issued, and you receive the hard copy the odds are the NVC have received your petition too.
Now you can call them to find out your Visa Case number.
Get your Visa Case Number
You need to call the NVC to get your Case Number as follows (waiting times can be long, and sometimes when busy the call may not go through or lines will drop). Both the petitioner and beneficiary can call. If you aren't in the USA, then you can make the call for free using you Gmail account.
Phone Number: +1 (603) 334-0700
Hours: Monday through Friday from 7:00 AM to 12:00 AM (Eastern Time)
You need to have the following information to get the case number from the NVC, they may ask you for your NVC Case Number but explain that you are looking for it:
USCIS Receipt Number (it is on the USCIS Notice of Action letters)
Petitioner’s Full Name and Date of Birth
Beneficiary’s Full Name and Date of Birth
Track the Progress
Go to the CEAC Visa Tracking website, and enter the case number you got from the NVC.
You can track all the way from the NVC to your consulate receiving the I-129F petition, then you are ready to submit your part of the K-1 Visa application (DS-160).
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