Elizabeth Berkley -- I'M PREGNANT (I'm So Excited!)

Elizabeth Berkley is with child ... this according to Elizabeth Berkley.

The former "Saved by the Bell" actress -- married to artist Greg Lauren -- debuted her baby bump in L.A. today. It's the couple's first child.

Obviously, the 39-year-old is super fired up about the situation ... telling TMZ, "In life there are moments you cherish forever and this is one of them."

She adds, "We are so excited to share this moment and special news! The baby is due this summer"

Mazel tov!