Jennifer Aniston consults a fertility doctor

L&SCover(1136).jpgJennifer Aniston and boyfriend Justin Theroux have been glowing with joy lately--and now, the couple may have reason for even more happiness! Life & Style has learned that Jen has been visiting a fertility expert and is ready to start a family with Justin -- she's even hoping for twins!

"Jen was seeing ob-gyn Dr. Robert Katz in Beverly Hills regularly this spring to see how fertile she is," an insider close to the actress, 42, tells Life & Style. "She had a million questions about getting pregnant after 40, and just what is involved with in vitro fertilization."

Indeed, statistics show women have a one-in-four chance of conceiving twins when they undergo fertility treatments. "Jen's doctor asked Jen pointblank if she's okay with twins," says an insider. "She is!"

And this is not Jen's first time seeking consultation from a fertility doctor. As Life & Style first reported in 2009, she consulted with pal, ob-gyn to the stars and fertility expert Dr. Mary C. Kerr. Jen's already started preparing by giving up some bad habits. "She hasn't had a cigarette in months," reports the second insider. "She gave up caffeine. She isn't drinking alcohol." An eyewitness tells Life & Style that Jen stuck to nonalcoholic beverages at pals Ellen DeGeneres and wife Portia's recent party for their third anniversary.

"Jen has her fingers crossed that she will be a mom by next year," says the insider close to the star.