According to TMZ, the 21-year-old is having a baby with 20-year-old school teacher Sunny Oglesby, who he has dated for just over a year.
The Alaska inhabitants are said to be in the early stages of pregnancy, with a source adding that they are "so excited" about starting a family.
Johnson already has a child with Bristol Palin. He has reportedly complained that Bristol's parents Sarah and Todd Palin have prevented him from visiting his son, claiming they have lied about baby Tripp's whereabouts.
As a result, he is not believed to have seen much of the toddler, who was born in 2008 when Bristol was 18.
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