For reference, they're not just going after Instagram-related businesses: https://www.theguardian.com/technology/2016/sep/09/instagram...
If you think this could become a big thing, either be ready for the battle and have lots of money, or rebrand now while you still can.
I know this is a hard pill to swallow, especially after you've registered the domain and everything — and it likely won't be a problem for you for a good while, but in the rare case of this hitting product hunt, or techcrunch, you may run into issues later down the road.