King Henry had a son after Mary what was his name?

The children, and their respective mothers, the wives of Henry VIII (1491 - 1547) are:

Mary I (1516 - 1558) by Catherine of Aragon - first wife (1485 - 1536)

Elizabeth I (1533 - 1603) by Anne Boleyn - second wife (c1501-07 - 1536)

Edward VI (1537 - 1553) by Jane Seymour - third wife (c1504-09 - 1537)

Catherine of Aragon did suffer stillbirth and miscarriages, as did Anne Boleyn.

Anne of Cleves (1515 - 1557)

Catherine Howard (c1520 - 1542)

Katherine Parr (c1512 - 1548)

did not bear Henry any children.

Henry also had an acknowledged illegitimate son:

Henry Fitzroy (1519 - 1536) Duke of Richmond (by Henry's mistress Elizabeth Blount)

There may have been other illegitimate children, possibly by Mary Boleyn, (and in particular her son, Henry Carey) another of Henry's mistresses and sister of Anne Boleyn; but they have not been confirmed or acknowledged, probably because of the timing of Henry's relationship with Mary Boleyn.