8 weeks today

I'm 8 weeks today and this would have been the day I started my period. I had some light pink blood on  tp and I freaked out. I called the on call dr and she told me try and not stress and come in first thing in morning for an ultrasound. She did tell me if it got worse or painful to go to the er. I'm just praying everything is ok. Has this happened to anyone on  here?