Weaver
Sage
Time period resembles ancient antiquity so definitely fantasy as opposed to sci fi.
Um... No. Time period is not one of the defining elements (as far as there is such a thing) between fantasy and science fiction. Julian May's Saga of Pliocene Exile comes to mind. It's science fiction, but the time period is a lot further back than, say, ancient Egypt. For that matter, there are plenty of emphatically fantasy stories that are set in the future. Shannara, anyone?
I generally think that alternate history (a story playing with "What if Rome never fell?" to use the cliche example) is science fiction, but an alternate world (not necessarily any magic, but it's not related in any way to our world) feels more fantasy-ish to me. Of course, I think that the "line" between the two is wide and blurry and not subject to simple definitions.