Nicholls is in the box seat to claim an Olympic berth in the discus as the only Brit to have thrown a London 2012 B standard this year.
However to rubber-stamp her selection she needed to finish in the top two at the Aviva 2012 Trials in Birmingham at the weekend and throw the all-important A standard.
A below-par throw of 52.21m - nearly ten metres shy of the A standard - and second place was what actually materialised for the 25-year-old meaning she will head to this week's European Championships still sweating on her spot.
British rival Eden Francis - who pipped Nicholls in Birmingham - could yet still beat her to London 2012 qualification and is in Helsinki with her with Nicholls acknowledging she's struggling to cope with the pressure.
"Since April, with the Olympics coming, it's all been a mind game which I'm not used to," she said. "I've never really had this mental pressure and stress before because I've never gone to the Olympics before.
"It's frustrating because I know what I can I do and I know I'm in good shape. It can come it's just whether it comes in the next competition or not.
"Eden Francis is more than capable of getting the A standard so I have to bear that in mind. I can't be cocky and say she's not going to get it because that would be very, very stupid.
"It's unfortunate that the competitions I'm doing are so squashed because it means I can't afford to take a week out just to train.
"I could do with not flying away, trying to find a good wind or a good level of competition where I can make the A standard. I could just do with a week off somewhere. But I just have to keep competing."