Unlikely if you're bleeding like a normal period. If it was only last week you had sex, it would be too early to know if you're pregnant. If you did conceive, then the egg would only just be implanting round about now, which can sometimes cause bleeding - but not as much as a period like flow.
Having sex can bring on a cycle if it was almost about to start, so that's possible. If you suspect pregnancy, wait another week or two and test adn see what it says.
I would take a test in 2 weeks!! Are u still bleeding?