I need some advice 😔

Yesterday was my first appointment. I have been having quite a bit of cramping, so the scheduled and ultra sound right then and there. It seems as if I am only 5 weeks 6 days, due June 30th, when my calendar puts me at 6weeks 6days. The unltrasound showed our baby, with a weak heartbeat. I will be going back on the 14th for an additional ultra sound. Has anyone had a positive outcome from this? I know i shouldn't be stressed out about this, but I can't help think the worst. Maybe i just need words of encouragement. I can't shake the feeling the worst is going to happen. 😔