Bloody mucus before and after my period. some fresh blood and dry blood clots, too. is this cancerous?

Unlikely but see gyn: There are many more things that can cause that other than cancer. The best initial approach is to visit your gyn and have a physical exam. They can usually no needed ultrasound procedures in their office and then determine along with bloodwork if anything further needs to be done to figure out the causes. Cancer is possible but less likely than more benign causes.