Incredibly frustrated!!

KB
So March 26 I get a bfp! And me and my husband were super excited. Well I go to my gp not my ob, and get a blood test and its negative. With that news I just began to believe it was a chemical and I would have my period in a few days. Now it's April 8 and no bleeding. No signs of af showing her face. Should I keep small hope and retest in a few days? Any advice greatly appreciated! This is my test. The top is an Opk