Kate's baby bump starting to show as second trimester progresses

Catherine, Duchess of Cambridge may only be about four months along, but on her tiny frame, the baby bump is already showing a little bit.

Kate was spotted out on a shopping excursion in London and as you can see in the above video, she's got a small little bump beginning to show on her belly.

A royal source tells US Weekly that Kate is "arranging meetings with the charities she is involved with and planning future engagements before the baby is born. She wants to keep herself busy now that she is feeling better."

If you'll recall, Kate was hospitalized back in December with acute morning sickness. But the second trimester typically is a lot easier for pregnant women and Kate appears to be feeling good.

Prince William and Kate due in July.