FIRST PIC: Pregnant Kate Hudson Debuts Her Baby Bump

Credit: Dimitrios Kambouris/WireImage.com; PITTAM/JFX/XPOSUREPHOTOS.COM

It's baby bump Hudson!

After several weeks M.I.A., Kate Hudson emerged out of hiding on Monday morning, arriving at London's Heathrow airport with beau Matthew Bellamy -- and showing off her baby bump for the very first time.

At first revealed at Us Weekly, Hudson, 31, is now about 16 weeks pregnant with the Muse frontman's child.

It will be Hudson's second little one; she has a 7-year-old son, Ryder, with rocker ex-husband Chris Robinson.

Hudson's famous mom Goldie Hawn arrived in London a few days earlier to present at the British 2011 Comedy Awards -- and gushed to UsMagazine.com about her newest grand-baby-to-be.

"I'm excited! It's exciting," Hawn, 65, told Us Saturday of her daughter's pregnancy. "We're just all very happy... happy for them both. What's more to say?"

Hudson and British musician Bellamy, 32, have been dating for nine months. The pregnancy "was not planned, but they are excited and embracing it," an insider revealed to Us.