Low heartbeat Rate @ 6W5D

Hi All Mums-To-Be I am in my 40s and this is my 4th child - considered high risk pregnancy and risk of miscarriage. Just went for my 2nd ultrasound and heard baby heartbeat for the first time However based on gestation, the heartbeat Rate is deem low. It shld be at least 110 while now it is 80 Just need some form of support and encouragement from the community here Thank you