Thin on the Ground?

Almost May, and here's a funny thing - I've yet to see a single Red Admiral. I've seen Commas galore, Peacocks galore, Brimstones galore (when the weather's relented and we've had some warm sun), and recently Orange Tips, Small Whites and Holly Blues - but still no Red Admiral. Normally it's my first or second sighting of the year, and the most frequent of the early (and late) fliers, but not this year. Even if I see one tomorrow, it will be the latest first sighting I can remember - and an unheard-of seventh on my list.
Is it just me, or are the Red Admirals unusually thin on the ground this spring?