Her biological clock must be ticking!

Britney Spears grabbed Starbucks in L.A. today amid rumors she is eager for her Las Vegas residency to end in 2015 so that she can have a baby with boyfriend David Lucado!

Although executives are allegedly eager to extend her concert series through 2016, Brit Brit is counting down the days until her contract is up and she can try for a child with her beau.

"Britney cannot wait until the Vegas show is done because she wants to start a family with David. She says she will get pregnant as soon as the show is finished! David is always with her in Vegas and they act like an old married couple together. He is really good with her kids and has taken to the father role pretty easily," a source dished to Radar.

Already mother to sons Sean, 8, and Jayden, 7, the pop princess is hoping to have a daughter next! "I would really like to have another baby, a girl. I think she would be like a mini-me. I think it