No it'll drain just fine perlite takes some beating in that department, I used perlite in the past it's a great substrate imo.
As long as you keep it damp it'll be fine, you'll see moisture gathering under the top, you'll also see and feel it's different to dry perlite.
A tip... Cover your pot walls with black and white, the white pot lets light through and the perlite goes green with algae.