That site that said he was 3 in 1967 is run or edited apparently by Barnett an award winner at CBS.
http://www.theobamafile.com/ObamaFamily.htm
“It’s understandable that Obama overlooks the particulars, since Ann Dunham was probably a minor when Barack Obama Sr., an already married 24-year-old, impregnated her?
Obama weighed eight pounds, two ounces when he was born on August 4, 1961 (p. 22 of Dreams from My Father), so we can assume he went close to full term, or nine months.
His parents marriage took place six months before his birth on February 2nd, 1961. Nine months before Obamas birth would be early November 1960, about three to four weeks before Ann Dunhams 18th birthday on November 29, 1960...”