His only other Swans goal came in April 2009 in the 2-2 derby draw with Cardiff at Ninian Park.
"My first is a very memorable one for obvious reasons and it's been a long wait in between which is slightly disappointing," said midfielder Allen.
"But hopefully this will give me the confidence to get on the score sheet a bit more often."
Third-place Swansea travel to Championship leaders Cardiff for the season's first south Wales derby.
Cardiff are unbeaten in seven and on the back of five straight victories, while Swansea are unbeaten in six league games, picking up four wins, but have not conceded in the last five games.
"The last couple of years it's really come to note how well Welsh football is doing and both teams are progressing really well," said Wales international Allen.
Allen pleased with Swansea goal
"That's going to add to the excitement of the game. I think it's probably the biggest one in recent times and I'm sure it's going to be great for both sets of supporters and players alike."
Cardiff will be without 12-goal top scorer Jay Bothroyd who picked up his fifth booking of the season in the Bluebirds' 3-1 win over Norwich City on Saturday.
But the Swans will also be without influential midfielder Darren Pratley also picked up a fifth booking in the win over Crystal Palace.
"It's devastating for him," added Allen. "Everyone wants to be part of the derby and he's got a great track record in these games and he's going to be a big miss for us."
Source: BBC Sport
Source: BBC Sport