Is my baby safe if I've used Latisse for the first 12 weeks?

The medication is applied superficially and will most likely not cause any adverse effects to your baby. It is a good idea to discontinue use while pregnant or breast feeding. 

First,
congratulations on your pregnancy! LATISSE® is FDA-approved, however the jury
is still out on whether or not it's proven to be safe to use while pregnant or
nursing. The FDA issued a “Class C” rating to LATISSE®, which means that some
animal testing has suggested that LATISSE® might have a negative impact on
pregnancy. It's important to note that the animals in the test were given
approximately 41 times the human dose, so it's unlikely the health or safety of
your baby will be affected. However, given that LATISSE® is used for cosmetic
purposes, you may want to consider waiting until your baby is born and weaned
to continue using LATISSE®.

There is nothing to worry about, your baby will not have any adverse health issues because of your use of latisse but I would recommend discontinuing use until after your baby is born. Congratulations!