am I having a miscarriage??

Victoria
I got my BFP 1 week ago today and I'm now currently 4 weeks and 5 days, however, I kept testing and I had a positive clear blue digital on Saturday and I woke up on Sunday and got a negative in the afternoon, have since done more tests and the line is vvvvf, started spotting a tiny bit this morning, is this it? Am I having my 2nd miscarriage? Heart is broken. Have a doctors appointment this afternoon and hoping to get a blood test done but I think my chances are low for this to be a successful pregnancy, what is wrong with me?