I take cetrizine for allergies and hayfever and was told by my GP that if I was too uncomfortable without it to continue taking it as normal (nasal sprays and eye drops do nothing for me at all, these I think are usually recommended first but I didn't look into it as pointless for me). However I've actually managed without and am now hoping to hold off until birth now I'm at 38 weeks. She said they don't test the products on pregnant ladies and so there isn't enough data to know which is the best option. I would see a doctor first though, things change all the time.