Brown Stringy Discharge

Hello, I'm 7 weeks 3 days. A week ago at 6 weeks 4 days, I had some pinkish/red spotting that quickly turned into some brown discharge. I went to ER when I first saw the pinkish/red discharge. They did an ultrasound and said that as far as they could tell, everything looked as it should and the baby had a heartbeat of 124. They also drew my beta Hcg and it was 34,080. My OB drew a repeat beta hCG two days later and it had gone up to 55,000. When I went to the bathroom tonight, this was on my toilet paper when I wiped. Should I be concerned?