I have always had heavy flow when i am on my periond and it usually last 8 to 10 days sometimes longer is this normal? what about. blood clots?

Maybe: May be within normal limits but could represent a number of issues well discussed in this link http://www.Ncbi.Nlm.Nih.Gov/pubmedhealth/pmh0014910/ i would recommend consulting with you gynecologist who is expert in this area.

More than usual: Bleeding for 8-10 days is excessive and you should consult a gynecologist. Blood loss may cause iron deficiency anemia and you should take oral iron and multivitamin supplements. Blood clots also indicate excessive blood loss.