HSG concern, please help

Lyddie
Hello everyone, 
I had an HSG 2 days ago. It was ultimately painful and not a great experience. 
I was told to wear a pad and that of have light spotting while the dye made its way out. 
However, it has now been over 2 days and I am flowing heavy like a period. This is not typical of this procedure and I would love to know of anyone else's experiences with this? 
Anything will help. 
Thank you.