Most Helpful Guy
There are tons of caveats here. If I were 17, if I found her personality attractive and engaging. Then yes.
To start, I don't find pregnancy to be a turn-off. (In fact, when my girlfriend was pregnant with our children I not only found her to be incredibly sexy - baby bump and all - but the sex was in many ways more passionate. Very primal and instinctive for a man.)
Secondly, dating is not marriage and there is a part of any man that is, I think, naturally protective of a mother and her baby. (That whole evolutionary instinct thing again.) As a 17 year old guy, although I would probably be thinking of my own future (college and such), I could see myself falling for a gal and being very loving and nurturing toward her baby.
Of course, this is all abstract and specifics make all the difference. However, at the level of abstraction, there is nothing about it that inherently turns me off about it, and a few things that appeal.
Most Helpful Girl
I say avoid. Unless youve been secretly crushing on her for years and you are cool with her having a baba that's not yours that u will have to help with some day.