I am meant to be 6weeks and 4 days pregnant. went for a transvirginal scan which only showed a gestation sac and yolk sac no fetal pole. is this indicating a miscarriage . ?

Not necessarily: May be too early or a blighted ovum. HCG quant and repeat u/ s would help

Not necessarily: While it is possible that you are having a miscarriage, it may be that the pregnancy is just too early to see the fetal pole on US. Rescanning you in a week should reveal what you are looking for. In the meantime, watch for signs/symptoms of miscarriage - cramping, bleeding, etc. Good luck!