A little 5 wks, 3 days

I went to the ER last Friday evening because after working my pt I'm always very very sore from the lower abdominal and lower back down thru my legs, never any spotting or bleeding tho. My ft job I can sit whenever I need to. Well they of course confirmed pregnancy again, ran blood test and did an ultrasound (vaginal and abdominal). My sac is where it should be. She didn't see anything inside of my sac or the yoke. It was measuring a little further along than my LMP would say. They mentioned it possibly being too early, ectopic and tubal pregnancy. I am definitely freaking out. They told me to follow up with my OB of course. Trying not to worry about it. Should I be worried or am I just too early right now for my peanut to be seen?