The 31-year-old Pink, whose real name is Alecia Beth Moore, is 12 weeks along , Us Weekly reported today.
"She wanted to do it between tours, when she has some time off," a source said.
The Who Knew singer and motocross racer Hart, 35, were married in 2006. The pair separated in 2008 but began "dating" again and went to marriage counseling, which led to a reconciliation.
“Pink was determined to make the relationship solid," the source said.
"Now she’s really happy, and she’s excited she got pregnant so fast! She’ll be a brilliant mother.”