The options are all possibilities I've read on other sites. :)

I don't think she is pregnant. I really want her and Barney back together. but doing it by throwing a baby in there I think is a really bad idea. They both need to sort their selves out first before having to think about a baby!

^I agree, however this season is all about timing-you can't choose to accidentally get pregnant.

I feel the same way as you, paperstarfalls. I'm hoping this isn't true, that Robin isn't in fact pregnant, or that somehow they'll write their way out of this corner.

I Think she is pregnant but she doesn´t know who the father is..:)

If not and she really is pregnant I think she knows that the father is Barney...'cause I think her and Kevin always used protection, but when she cheated on him with Barney she didn't think about it

Not a false positive. B&T have confirmed.
She receives "bad news" in the next ep. My guess is that the bad news is Barney is the father...YAYYYY! :D

I think she is pregnant, the father is Barney, she will get accustomed to the idea of having a baby and then have a miscarriage
either way i don't really like where this is going

I don't think that the writers let a lily & robin pregnant .. I don't think they like.

Yeah, I think that she's going to miscarry too. :( Although I do kinda like Lily and Robin both being pregnant-just as the callback to Alyson and Colbie being pregnant at the same time.