As a matter of good medical practice,the precautionary principle is routinely adopted to ensure maximal safety to the developing foetus.Medical interventions not directly associated with the pregnancy itself or for critical medical issues of the mother are therefore not recommended.
The HPV vaccine falls into this category. Futher, although animal studies, human studies, human clinical trials and ongoing vaccine surveillance programmes indicate there is no known risk to either mother or foetus from the vaccine, pregnant women have been, for the reasons cited above, specifically excluded from cliinical trials etc, so there is little data directly attributable to pregnant women.
Best advice is to wait until after the birth of the baby, then go back when feeling up to it ;)