Allergy meds while TTC

Sarah • Mom of 2 (ages 14&11). TTC #3 since Jan 2014 with new hubby (his first). #1 miscarriage November 2015 :(
Does anyone know if allergy medication will affect TTC?
​I know it's a no no when pregnant but I wouldn't think it would stay in your system for long. 
AF just left and haven't BD'd since so no chance of pregnancy and my eyes are SOO itchy from allergies. 
​Any idea if it's ok to take a pill for some relief?