"This is a decision of mine that I'm not going to make today and I'm not going to make tomorrow," Phelps, 23, told the Baltimore Sun on Wednesday, after his daily workout at the Meadowbrook Athletic Club.
"It's going to require a lot of time and energy and a lot of thinking for myself. But also talking to Bob [Bowman, Phelps's coach] and talking to my family and just deciding what I want to do."
Saying he "clearly made a mistake" and felt embarrassed and uncomfortable, Phelps added, "Yeah, there are still goals that I have in the pool, 100 percent. But I'm not going to let anything stand in my way. If I decide to walk away, I'll decide to walk away on my own terms. If it's now, if it's four years, who knows. But it is something I need to think about and decide what I want to do."
Difficult to Tell MomPhelps also admitted it "definitely wasn't easy" to inform his mother, Debbie, who is a school principal, about the photo – and that it reminded him of his 2004 DUI arrest.
"This is just a stupid thing of mine that I did, and I have to live with it," he said, telling the paper, too, that he is not a regular pot smoker.
After last weekend's publication of the photo, which reportedly was taken in South Carolina last November, the local sheriff said he is looking into possible criminal prosecution against Phelps.
"This was stupid," said the swimmer, "and I know this won't happen again. It's obviously bad judgment and it's something I'm not proud of at all. I will say that with the mistakes that I've made in my life, I've learned from them. Every one of them. And I've become a better person."
He added, "That's what I plan to do from here. It's definitely not what I wanted, and it's clearly not what my mom wanted."