Reese Witherspoon -- Birthday Baby Bump?

Reese Witherspoon turns 36 today ... and she may be getting the best birthday gift ever if she really is carrying her first child with husband Jim Toth.

The same day news of her pregnancy was reported, Reese was spotted in a loose fitting black top and red skirt in L.A. on Wednesday.

While the Oscar winner has yet to confirm the baby news, she already has two kids with ex-husband Ryan Phillippe.