I need some advice please!

I had very bad bleeding yesterday I ended up going to the ER. And they did an emergency ultrasound an I couldn't see anything I'm suppose to be 10 wks an I dint see my baby. I was very sad an I felt like I couldn't breathe I started to have an anxiety attack! The nurses where very kind an started to calm me down. The nice Doctor walks in and says baby your not 10 weeks your only 6 weeks an showed me my precious angel but is so small! I don't understand how I'm 6wks?I found out I was pregnant 6 wks ago? I'm so confuse! So was I a day pregnant when I found out? Is that even possible? Has anyone else experienced this before? Any advice is very helpful thank u all in advance❤️❤️❤️ my last period was June 19 2015