last night my daughter mention there is some marks behind my knee then i saw in mirror it was dark purple veins behind knee,i want to ask what is the reason of purple veins and is it dangerous.my age is 36,I had preclamsia in first pregnancy other two are normal in third pregnancy Ihad heart pulptation ,heart rate was quit high it was 260 hospital had given me treatment in emergency,i was get pregnant in january of this year ,but i had terminate this pregnancy in fouth week after seven week of termination I got period then i started to eat contraception pill levlen ed ihave finished ful one and second one more then half then i wasn,t feeling good then i stopped it during this pill i was feeling high pulptation again.after stopping pill i got period after two days after that now i saw purple veins behind knee of left leg is dark and right leg is little bit light.I saw my GP for heart rate but he had recommend to see cadialogist,iam worried about all this situation,could you help me