The pair tied the knot in June 2017 and already have two-year-old Ella together, with Jacqueline also step-mother to Dan’s four-year-old son, Teddy, from a previous relationship.
Confirming the news in an interview with OK! magazine, Jacqueline shared: “We both started laughing when the test was positive.”
Dan added: “We hadn’t been trying so it was a huge shock.
“I think I’m still getting my head around it. Kids are a blessing but having three children is going to be a big responsibility. I’m not going to lie, I feel quite scared!”
Dan first shot to fame after appearing on ITV2 reality show The Only Way Is Essex, with Jacqueline finding fame in BBC One soap opera EastEnders, playing Lauren Branning.
The pair met in 2013 and got engaged two years later, months after welcoming baby Ella.
Jacqueline’s pregnancy comes ahead of her departure from EastEnders, with the actress being involved in a high-profile storyline that saw Lauren and her sister Abi Branning fall from the Queen Vic roof on Christmas Day.
Although Lauren survived the accident, with Abi being declared brain dead, Jacqueline is expected to leave the soap in the coming weeks, with her final scenes set to air in February.