Kim Kardashian and Kanye West are so excited to welcome baby number four, who is believed to be their last child. 

According to a source at People magazine, their gestational carrier for the baby is not the same one they connected with for daughter Chicago, who turns 1 on Jan. 15.

“Since they had another embryo, Kim and Kanye always knew they wanted to try and implant that embryo too,” the source stated. “They hoped to work with the same gestational carrier, but it didn’t work out this time. They are working with a second carrier now [who] is pregnant and will give birth in the spring.”

“Everything so far has been smooth,” the source continued. “Just like the last time, Kim is very involved with the carrier. Kim goes to doctor’s visits with the carrier and makes sure that she has everything she needs. She is a local woman with a family. Kim’s OB/GYN is overseeing her pregnancy.”

We can’t wait!