This may be considered among the most unlucky days on the calendar but not by the mother of the all-time Olympic great who is competing at the Edinburgh International swim meet which gets underway at the Commonwealth Pool tonight.

In mock sinister tones Natalie Coughlin, the Californian who matched the record for an American woman by bringing her Olympic medal to a round dozen in London, even wonders whether there was something happily ominous in that maternal defiance of superstition.

"My mom has always said 13 is a lucky number... so maybe it is for me. She used to say that when I was, like, five. Maybe she's psychic," she joked in pondering the significance.

Maybe she is, because for all that Coughlin has been involved in the sport for more than a quarter of a century, this superstar of swimming did not even take up the sport until she was six so there was no way of anticipating what she might achieve at that time.

Indeed, the record she has been poised to break since earning that 12th Olympic medal three years ago had not even been set since Dara Torres was the first American woman to reach the mark in Sydney in 2000, before Jenny Thompson matched her four years later.

Coughlin claims, however, that surpassing it is not uppermost in her thoughts.

"It's something that's in the back of my mind because it gets brought up so often and it's a huge deal, but that's not necessarily my focus," she explained.

"My focus is that I wasn't satisfied with the London Games and I didn't want to end a very long career on that note, so I needed to make some changes and going forward I'm very happy with where I'm at."

A central figure in US success at her previous two Olympics when collecting 11 of her medals, three of them gold, Coughlin ultimately had to rely on others' efforts having helped the team through the qualifying rounds in of the 4x100m relay before being left out of the quartet that contested the final.

"After London I realised I'm not getting any younger so I can't do 100 fly, 100 back, 100 free, 200 free, it's too much, so I needed to dial it back," she explained.

"Still the competitiveness inside me makes me want to do that and swim all those events, but I just know I shouldn't.

"Hopefully next year I'll be qualifying for my fourth Olympic team and things have been very different. After London I knew I had to make a change in training, so I spoke with my then coach and decided I had to switch teams and coaches.

"So now I'm training with Dave Durden and the men's team at Cal (Univerwsity of California). It was the change I needed... a different focus, a different training format and I started focusing on freestyle.

"I'm starting to add backstroke in a little bit now, but I just kinda needed something to jolt me in a new direction having been to London where I wasn't as successful as I know I could be, which forced me to make changes I was reluctant to make."

What is striking is that at 32 Coughlin retains an appetite to train and compete in a sport where so many are burnt out at an early age but, in what may serves as a salutary example to others, she admits to having gone through that and come out the other side.

"I've been training at a very high level for at least 20 years," she said.

"It's interesting, after my 2008 Olympics I needed at least a year off. That was my first thought. I wasn't even done with the Olympic Games and I was already fantasising about my time off and I ended up taking a year and a half.

"However as I've gotten older I've realised more and more I'm so lucky, this is the coolest job. I love to be fit. I like to work out and I like to travel the world and compete, so if I can do this at a high level and still do this as my job then why not?

"I mean I'm not going to be able to do this forever so as I get older and see my friends in their real jobs in the real world I realise this is pretty darned great, so I want to do this for the next 18 months and then I'll re-evaluate. At 21 and 24 I was like 'I need a long break, this is too much,' but maturity sets in and you realise how lucky you are."

Coughlin is entered in the 50 metres freestyle and 100 metres backstroke tomorrow (Saturday) and the 100 metres freestyle and 50 metres backstroke on Sunday but admits she may have to trim that schedule down.