I have to say, I absolutely loved that episode. It was so good and heartwrenching. It was very interesting to see Lucas in Dan's place for a second. I think that was the best Chad and Sophia had acted the whole season. I was so proud of Lucas when he was taking the responsibility and trying to be there for Brooke.
Some really good quotes from that episode-
Karen Roe: [after finding out Brooke is pregnant, Karen has slapped Lucas] Lucas! I didn't mean it.
Lucas: I'm pretty sure you did.
Karen Roe: No! It's just - do you understand? This is *exactly* what I didn't want for you! I mean, have I been talking to myself for the last few years? You have so much left to do in life! So does Brooke. Oh God, you're both just too young for this.
Lucas: Don't cry, Mom.
Karen Roe: It's just that I'm scared for you. I can't believe this is happening.
Lucas: How close was I to not existing? Dan wanted an abortion, Mom. Why didn't you listen to him?
Karen Roe: Because I realized... I wanted you in my future.
Lucas: My dad didn't want me, okay? Not just that he didn't want to claim me. He didn't want me to be born. Now I always thought that when I started a family, I'd be older and settled and I'd be...
Brooke: In love?
Lucas: Yeah. But so did my mom.
Lucas: No, look - this whole thing scares the hell outta me, okay? But whatever you decide to do, I'll be there. And if you're not ready, then you're not ready, but if you wanna have this baby - then so do I, and whatever it takes for me to be a good father, I'll be there. Always. I promise you. I won't let you down.
Brooke: I lied.
Brooke: I'm not pregnant.
Lucas: Wha - But I saw the test.
Brooke: I know. And when the doctor called, he said I wasn't pregnant. He said that can happen.
Lucas: Okay, no-no-no-no no. I-I-I was standing right there when he called.
Brooke: And you had just called me a slut.
Lucas: So you lied to me to punish me? How could you do that?
Brooke: How could you cheat on me with my best friend?
Lucas: Brooke, I never meant to hurt you.
Brooke: That doesn't really matter, Lucas. 'Cause in the end it all hurts just the same.