You'll have to estimate, not having an OG (original gravity) reading. Normally, you compare the OG with the FG (final gravity) and there's a calculation that allows you to determine the approximate ABV.
So anyway, you can estimate...if you know the amount of honey and the total volume of your primary, you can calculate what the OG *should* be...it's not always spot on though, because the actual sugar content of honey varies somewhat by variety and season...
Packaged: Red X Weimea SMaSH
Recent Meads: Mead Day '11 Ginger Metheglin, Mead Day '12 Traditional (orange blossom) Mead, Simple Cyser '12
Secondary: Why do I keep this line here...?
Bulk Aging: Cocobochet, Wild Cider, Simple Cyser
Planned: Hop Metheglin #3 (NZ hops), Trad. Gesho T'ej