Check the box/container they are in, it might say 'do not take if pregnant'. I think you should also check with a doctor.

I started having really bad problems with allergies around 6 weeks or so, I finally decided I couldn't suck it up any more and went to my Dr. They told me that claritin 24 was one of the safest during pregnancy, i've been taking it since. You can get it over the counter.

Thanks guys, thats a big help :)