OG reading after pitching???

Yes, it's an obvious mistake but since I put 2.2 pounds of both DME and dextrose into this brew I was interested in it's overall alcohol content so I took a reading after I pitched the yeast. My concern - do you think I'll miss out entirely on an accurate final alcohol level calculation because the yeast made the mix denser than it otherwise would have been and therefore the OG reading inaccurate?

Thanks for any insight,
Fred

I've seen and know plenty of people that take their OG sample after pitching, I don't think the yeast, even a 1L starter is really going to impact the specific gravity enough to throw you off.