Do you know when you ovulated? That's probably the most important thing. If you ovulated around the time you had sex then you could be pregnant. However, since you say you're 9 days late it sounds like your period was due around the 7th of April, and it is doubtful that if your period really was due then that you would have been ovulating around April 1st. If that's the case then it's very unlikely you're pregnant. Did you end up taking another test or getting your period?