Moose- are you only have one dose of pregnyl on Tuesday? If so then 3 days. However, those who have follow-up, eg day 3,6,9 after EPU or ET will have a bit of a build up so maybe 7 days.
My own experience, I have the 3 shots of pregnyl after EPU at day 3,6,9 and at 3 days after my last pregnyl shot, it's still a faint positive on HPT. 4 days after, it's a negative. Hope that helps.