Miscarriage January 18th Can I be pregnant?

Okay so I just recently had a miscarriage January 18th. I had only found out that I was pregnant on January 15th. My boyfriend and I have been together two years and gave up trying a few months back. I was charting my temps and using preseed with no luck. Then around January 13th the nausea and constant runny nose started. Within a few more days I was just really tired, my boobs hurted, and my sense of smell was sensitive that's what made me test using a first response. On January 18th I started spotting at work, so I went to the ER with my boyfriend right after and did a urine test that came back negative. They did a blood test, and my level was only 5.7. I was devastated because I knew that meant my level went down from when I did my at home to now. By the time I got home my flow was heavy. My last period before that was December 15th so I was almost five weeks. Now here it is February 17th and I'm now two days late with absolutely no sign of af. I feel EXACTLY like I did last month, and I just don't want to test and it's negative or the same thing happens to us again :(