On Saturday I opened up the back door and saw a dark colored butterfly that I thought may have been a swallowtail. I wasn't able to see it close enough to say for certain.
But later, I went and checked my parsley plants - and guess what? There were Black Swallowtail eggs there!
She only laid eggs on the plants in front of out house though, that gets morning light. I have some more plants in the back, but couldn't find any eggs on those. It seems that last year the Black Swallowtails seemed to like the plants in front of the house better too.