Manufacturers’ restrictions prohibit this, but you may be able to get a prescription for these from your GP.
Loratadine and cetirizine are the tablets most often prescribed for hay fever during pregnancy because neither causes drowsiness.
Chlorphenamine can also be prescribed for use during pregnancy, but it can cause drowsiness, so is not usually the first choice.
Generally, nasal sprays and eye drops are considered to be the safest forms of medication for pregnant women.