Swallowtail Butterfly

While sitting in our sunroom this morning I was watching all the birds on our flowers outside in the back yard.

I then spotted this beautiful swallowtail butterfly. I am not sure if it's a black swallowtail or a spicebush swallowtail. If anyone can identify it for me, I would be so grateful.

This photo probably isn't the best technical shot as it doesn't follow the rule of thirds, but I still like it.

Also, I want to thank all you lovely people for putting my cute chippy on the spotlight page the other day! Thanks so much! That almost never happens.