12 week scan worries

Hello! I know I'm probably being completely paranoid but I'm have proper anxiety about my 12 week scan. I've had all the symptoms... Sickness, nausea, tender breasts, food aversions.... And I still have good days and bad days with these! I just can't shake the feeling that I'm going to get bad news at my scan (which is on Wedbesday). Not many people know that I'm pregnant, which makes it even harder. My husband has been really supportive and reassuring but the feeling still won't go. 
My sister in law (completely innocently as she has no idea I'm pregnant), sat and told me that a girl on her work went for her scan last week and they couldn't find a heartbeat. This has freaked me out even more. I know there are always possibilties but I'm needing some reassurance ladies. Please help.☹️☹️