Could Prolonged Periods Be A Symptom Of Pregnancy?

my monthly bleeding is for 5-6 days. now its above 15 days bleeding does not stop. during this session I had done sex for 2 - 3 times but using comdomn. Is this the sign of pregnancy. Please suggest

I am 32 years, weight is 52-55 approx. and have a child of 5 years. I dont want the child now so please suggest