I am just curious, because I was reading some of the women's health issues here regarding periods and clots -- what size is considered large for blood clots? What size is large enough to start causing concern? What is normal?

I am just curious, because I was reading some of the women's health issues here regarding periods and clots -- what size is considered large for blood clots? What size is large enough to start causing concern? What is normal?
After having a baby I was told to look out for clots the size of a 50p coin and when I started using the pill the doctor told me to look out for cots the size of a 50p coin I have never had and e that big so not sure what it all actually indicates all I no is 50p coin is classed as too big by my doctor xxx xxx