HCG levels didn't rise

I am 4 weeks and 4 days. I had Bloodwork done last week to confirm early pregnancy and they wanted me to come back for another check. They just called to say my numbers didn't go up. I have no symptoms like bleeding or cramps. I haven't felt as pregnant these last few days. I go back Thursday to test my blood again but it's not looking good. Is there anyone else that has had a similar experience?? And what was the outcome? I'm sure it's most likely a sign of impending miscarriage :( :( we were so excited after TTC#2 for 7 months.