Helo need answers

Hello all. Let me explain my background. At 20 years old ive expierenced and threatened miscarriage. Then at 23 i gave birth to a healthy baby boy who will be 4 in october. No complications during that pregnancy. I am now 27 and i am 6 weeks pregnant and ive started spotting on saturday. The spotting turned into heavy bleeding with passing blood clots and period like cramps. Today i am bo longer passing blood clots and the heavy bleeding has turned into spotting again. I went to the er and my hcg levels were at 350 yesterday july 24th 2016. Ive made an apot to see if everything is ok. Does this sound like a miscarriage or does this sound normal? Has anyone experienced this before and did your lo end in miscarriage or continued a healthy pregnancy?