It is a class B drug and no evidence it is harmful during pregnancy (based on testing on pregnant animals). However, like any drug, you should consult with your doctor before taking it. I think I read that it doesn't raise your ph as much as some of the other antihistamines so if you are trying to keep ph low ttc a girl that makes it appealing, plus you don't need to sign for it and can just buy it over the counter unlike Sudafed (see below)
Sudafed -- As of 9/30/06 – a new sudafed law took into effect. Every single product containing pseudoephedrine (PSE) has to be either in a locked cabinet or behind the counter. Also all sales of PSE containing products need to be logged in a book with a drivers license number, address, reason for taking it and signature. This is to “Curb the production of Methamphetamine”. The daily limit is 3.6 grams of sudafed and the monthly limit is 9 grams of sudafed.