Brown spotting... SCARED

I recently found out I was pregnant again immediately after I had a miscarriage at the end of March. I'm about 6 weeks along and last Friday had my first ultrasound. They were able to see the yolk and gestationaL sac but no fetal pole yet which I know is normal for how early and I was fine with that. However last night I starting having some brown spotting and light cramping. I am about to break down and am terrified im losing this baby too. Does anyone have any insight into this?? Please Help!