« Reply #33 on: Tuesday 15 June 10 08:51 BST (UK) »
the only John Loveday & Martha marriage at that time is
John Loveday june qtr 1866 Highworth vol 5a pg 15 with Martha Titcombe on the same page
So they would have been married at the time of Thomas' birth and the birth cert you have has Thomas born to an unmarried Martha.
1871 census has Emma Titcomb, Martha's sister, visiting them. They also have a 4 year old son called Alfred, so not much time to allow for the birth of a Thomas anyway.
If Thomas had been born to this couple before their marriage, he should have been registered as Titcombe.
The 1869 marriage has no Martha with the same GRO ref, there's a Mary Harriet or a Jessie.
Cornwall: Allen, Bevan, Bosisto, Carnpezzack, Donithorn, Huddy, James, Retallack, Russell, Vincent, Yeoman
Cards: Thomas (Llanbadarn Fawr)
Glam: Bowler, Cram, Galloway, James, Thomas, Watkins
Lincs: Coupland, Cram
Mon: Cram, Gwyn, John, Philpot, Smart, Watkins
Pembs: Edwards (St. Dogmael's)
Yorks: Airey, Bowler, Elliott, Hare, Hewitt, Kellett, Kemp, Stephenson, Tebb