Cetirizine does not affect any type of contraception clinical the contraceptive pill because this the morning after pill. It will also depend on how many weeks pregnant you are and the reason you need to take cetirizine.
Possible side effects of Cetigen include:
Cetigen is used to treat diseases such as: Allergic Rhinitis, Urticaria.
If you forget to take a dose, take it as soon as you remember if it is within two days of when you should have taken it.