Hi, I Am 2 Months Pregnant And Am Allergic To

Hi, I am 2 months pregnant and am allergic to dust. We just got a new air conditioner and heatin unit and am waiting for the ducts to be cleaned. The new unit is from what I think blowing old dust and stuff up from the vents. Website states I should ask doctor about benedryl. When I am home I cannot breath at all out of my nose, and my throat was sore all day yesterday.