The little boy from Jeanette, Pa., suffered from leukemia and other complications from genetic disorder Fanconi anemia, according to CNN.
"At 8:18 my son took his last breath in my arms," his mother, Christine Swidorsky-Stevenson, wrote on Facebook Monday night. "Im so sad upset and im in disbelief he is with angels and he's in no more pain. no more sickness no more hospitals."
Logan's parents, Swidorsky-Stevenson and Sean Stevenson, had planned to get married in July 2014 after postponing the wedding two years, hoping their son's health would improve.
When they learned that their son had only weeks to live, Christine and Sean moved up their wedding to Saturday.
"Under the circumstances of what the doctors told us, we just decided to go ahead and do it while he is still with us," Stevenson told CNN Pittsburgh affiliate KDKA.
For the wedding, Logan donned a tan suit and orange shirt that matched his mother's bouquet. And while his mom walked him down the aisle, according to CNN, he spent most of the ceremony in his grandmother's arms, close to his favorite brown teddy bear.