The actress, who recently bowed out from her role as Pat Evans after 25 years, was presented with the 'Lifetime Achievement' prize at Saturday's ceremony in London. Charlie Brooks (Janine) and Sid Owen (Ricky) handed over the gong on the night.
St Clement today (May 1) told Loose Women that she had no idea of what was in store as her ex-colleagues kept her in the dark.
She laughed: "[It was] extraordinary! They said, 'Lifetime Achievement Award', Phillip [Schofield] was doing his usual wonderful thing and Sid and Charlie came walking on.
"I thought, 'Oh, that's interesting - must be something to do with 'Enders'. Then they started talking and slowly it started to drop! And I thought, 'Oh, you b**tards!' And do you know, I was actually entertaining some of them in my home only a week before."
The 69-year-old added that she is enjoying her new role as This Morning's animal expert and has no regrets over her EastEnders exit.
St Clement said: "Funnily enough, I think that since the beginning of the year it's been an opportunity to reclaim myself a little bit, in a strange sort of way. So I'm not missing Pat. I've put her to bed.
"If I started down that road, what's the point of regrets? You do something in life, you make a decision, go with it and stay with it. Even if you decide it's the wrong one, and I can't say I've made that decision yet - I might do in a couple of years - you do it and get on with it.
"The thing is, I've said to myself and my agent, I want to do things that are actually quite light and joyful. I think it's nice that I'm doing my This Morning slot. It's lovely to do that, because I'm me. And I think sometimes it's a surprise to people to see that 'me' is very different from Pat."
The British Soap Awards 2012 airs tomorrow (May 2) from 8pm on ITV1.