ECG, ECHO,TMT report are normal before one month .cardio Dr. Says all normal don't worry . But sometime I have feel chest pain that time my oxygen level or heart beat in oximeter fall down 85 and 56 from 98 and 90. I have also constipation problem from 9 month but this problem now better gastrointestinal Dr. Normal report this pain  from anxeity. But mild anemia Hb level 7.7 with variant size RBC cell . When this pain start in left side chest and back side after that pain  in left hand. Plz suggest this pain panic attack or heart attack