Country Star Expecting Third Child

There's another baby on the way for the country crooner and his wife Heather, his rep confirms to PEOPLE. In addition to the couple's 20-month-old daughterDylan River, Nichols is also dad to Ashelyn, 15.

"Joe, Heather and Dylan are very excited to be welcoming a new baby by summer," his rep tells PEOPLE.

Nichols, 37, announced the news Thursday on Twitter.

"Aaaaaaand we're pregnant again! Another baby Nichols on the way in 2014!" he wrote.

This is especially happy news as the couple, who have been married since 2007, has been open about their difficulty carrying a baby to term. Heather suffers from an auto-immune condition which led to five miscarriages before fertility treatments and a number of specialists helped her to successfully deliver Dylan.