(In order of preference)
1. Somehow Zod impregnated her really REALLY quickly. He did have superspeed after all, right? (I like this one!)
2. Lex has secretly still got a bit of Zod in him and since Zod really was all about the breeding, Lex has been poking holes in condoms with needles prior to sex. *nods*
3. For nefarious reasons that I cannot yet fathom, Lex himself wants Lana to be pregnant and therefore tricked her (either with pinpricked condoms or placebo pills). The question, though, is why?! I haven't worked that out yet.
4. Lionel is secretly pricking holes in Lex's condoms. I'm rather fond of this one too. :-) Alternatively, he's bribing Lana's doctor to give her placebo pills. In this possibly universe, I fully expect that Lionel will sweep in and 'protect' Lana by delivering her child in private and 'taking care of it', thereby acquiring another Luthor labrat for Lionel to mindfuck. Nice!
5. Accident. And hey, those DO happen. Not often, but they do.
It's got to be one of these because I just don't buy that Lex is not all about safe sex. And while I can just about imagine Lana caught up in a romantic moment, and while that toga really didn't have any pockets, I just cannot imagine that Lex doesn't have stashes of condoms all over that mansion for precisely this purpose. *stabs*
Does Lex know she's pregnant? Yes. Surely, he must!? He has surveillance all over the place. I'm now fanwanking the problematic table as his secret sign to her that he knows and is not happy that she hasn't fessed up yet.
Now can they PLEASE start throwing things at each other (and then falling into bed with one another to have make-up sex) or something because the ice is killing me.