It wasn’t your imagination. According to the US Earthquake Event page, there was a 3.6 earthquake 15km W of Lofall, Washington, happening just before 9 pm.
The magnitude was measured at 3.6 (give or take 0.1), and it happened 54.1 km beneath the ground (give or take 0.7 km). It happened at 8:55 pm (Pacific Time) on June 15, 2017.
About 340 people did report feeling it in the US.