Pollinating Early Plum/Cherries In Western Washington

Hi everyone, and thanks for taking the time to read my post. I have some hybrid stone fruit trees that seem to flower earlier than the pollinators come out. Their flowers are done by early april. Does anyone have pollinators out and about around then? Im not sure if I just live in an early-pollinator desert or if it's a general climate thing. I live in seattle. Thanks!