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Baby number three!

Us Weekly is reporting that Keri Russell is expecting a child with her "The Americans" co-star, Matthew Rhys. The pair first stepped out as a couple in April 2014, following months of speculation that they were in a relationship. Less than a year later, that relationship seems to be moving to a whole new level.

The magazine's sources claim Keri is four months along. Neither of the pair's reps would comment on the pregnancy, but a source close to Matthew stated, "It's so exciting for them!"

The two are currently shooting the fourth season of their hit FX show, and are frequently spotted together around New York City.

Keri has two children from her previous marriage, son River, 8, and daughter Willa, 4. The actress was married to Shane Deary for seven years, before the two split in December 2013. Rumors swirled that the former "Felicity" actress was involved with her Welsh co-star shortly after the divorce.