The body of Princess Diana showed no physical signs of pregnancy, Robert Chapman, the pathologist who carried out her post-mortem, told the inquest on Monday into the death of Diana and her lover, Dodi al-Fayed.
But Chapman acknowledged that while her womb and ovaries did not show any of the normal signs of pregnancy, those would not have been seen if the pregnancy was less than three weeks old.
"No, I did not," he said when asked if he had noticed any sign of pregnancy.
"If one is dealing with a pregnancy, the appearance will vary depending, of course, on the duration of that pregnancy, but an established pregnancy will show as a change in the size of the uterus, a change in the thickness of the lining and the presence of a gestation sac," he added.
Dodi’s father, luxury store owner Mohamed al-Fayed, says the couple were killed by British security services in a high-speed Paris car crash in 1997 on the orders of Prince Philip, Queen Elizabeth’s husband and Diana’s former father-in-law.
He says Diana was pregnant with Dodi’s child.
British and French police investigations have concluded that Diana and Dodi died because their chauffeur, Henri Paul, was drunk and drove too fast through a Paris road tunnel, crashing the vehicle into a pillar.
Chapman said a pregnancy of under three weeks’ duration would not necessarily have been noticeable.
"I would say that from day one to seven, one could not or would not see anything. From day seven to fourteen, one might see something, although it is rather unlikely," Chapman said.
"Thereafter, there is an increasing likelihood of being able to see things which would indicate pregnancy," he added.
The inquest also heard that Diana did not appear to have drunk any alcohol in the hours before her death, although tests showed that Dodi Fayed — who dined with her that night — had.
Under British law, an inquest is needed to determine the cause of death when someone dies unnaturally.
The inquest, expected to last up to six months and cost up to £10-million, was opened after the conclusion of major British and French police investigations.