I dont think the height has anything to do with being pregnant. As far as I see, ppl back in the days were shorter and they could still have kids! Of course u being a tiny thing, it might be a little harder on ur lower back then most of us.
If u are talking about u cant get pregnant having intercourse, I am sure there are lots ways, perhaps they can plant ur egg into another woman's body and ur husband or bf's sperm...U get the picture.
So dont worry much, since there arent too much info on ur concern, u can always ask ur gyno.