Yeah, most likely you just caught something and it just happen to hit you after smoking. Happened to me a while back. The day after picking up a new sack I felt like shit. I thought it was the weed until I realized my 2yo daughter was sick too.

The other possibility is that the weed could be moldy and you're allergic to mold, or the grower used something that you're not reacting well to. Wait a couple of days until you're feeling better than smoke it again. If it was the weed you'll be sick again. If not you'll just be happy and high.