Where Are The Lilacs?

Just noticed, while I was eating frozen pizza in the dining room just now, that I didn't see the lilac trees in my backyard didn't bloom.  They usually bloom some time in late April/early May, if I'm not mistaken, but only for a week.  Now, I've been hella busy, but I want to think that I would have noticed if the lilacs bloomed because they are pretty and fragrant, and I would've gone to the backyard to see and smell them.  I have yet to do that ... or did not do that, one or the other.  So it's possible I didn't notice, but it's more likely it hasn't, or didn't, bloom.  If not -- damn, what's going on?