Anxious

Hello ladies,
I'm about 6 weeks pregnant and I've been very anxious and worried since I found out. So far I've had very little symptoms that come and go. They mainly ease off at night, except for cramps, sometimes those get a little stronger. But my pregnancy symptoms so far have been sore boobs occasionally, mild cramps, mild backaches and a little fatigue here and there. My first appointment isn't till July 19th but the dr called today and wants me to come in for ultrasound next Thursday. I assume just to make sure everything is progressing right since my appointment isn't for awhile. When I did my round of blood work last week everything was progressing well. With this being my first pregnancy, I'm so anxious and worried bc I don't have many symptoms and they aren't severe. I'm afraid they will do an ultrasound and won't see anything or an empty sac or won't find a heartbeat. Does anyone else share this same fear or have some encouraging words for me? This next week is going to be so long.