Reese Witherspoon is getting a very special birthday present this year. The This Means War actress, who will be celebrating her 36th birthday on March 22, is pregnant.

""Reese is right around 12 weeks,"" a source tells Us magazine. But she's ""not planning to announce it.""

This will be Witherspoon's third child, but first with new hubby Jim Toth. She already has daughter Ava, 12, and son Deacon, 8, from her previous marriage to Ryan Phillippe.

Witherspoon's happy news comes as no surprise. She reportedly has been trying to conceive with Toth, who she married on March 26, 2011. ""Reese and Jim have been trying to get pregnant,"" admits a friend of the couple.

""The timing is right,"" another source says. ""She's so happy!""

Congratulations to Witherspoon and Toth on this exciting news!

[Us magazine]