Pregnant with horrible allergies!?

I'm past 12 weeks pregnant now, and for the last week, my allergies have been absolutely awful. I'm the kind of person that doesn't want to take any drugs if they don't have to, especially during pregnancy.. But I am beyond congested, and my eyes are constantly itching, it seems I need to try to take a medicine at least to see if there is any relief... I called my doc, and one of the nurses said it was ok to take Zyrtec, has anyone else taken this when pregnant? Also, are there eye drops that are safe to use during pregnancy?? Does it pose a risk to NOT treat the allergies and be congested instead? Thanks for the help.