Like what Federico said it takes time for these pages to get found and indexed.
Moz's isn't able to index the web at the level that Google is able to. So just because it's not showing up in Moz yet doesn't mean that Google hasn't found and indexed it yet.
Other ways that you can monitor inbound links:
- Set up alerts with Google Alerts & TalkWalker.com
- Check referrals in Google Analytics, new referrals sources could be from other sites linking to you.
- Other backlink checkers that you could check, besides OSE, ahrefs & majestic seo
Hope this answers your question.