pregnant....?

So me & a close friend of mine (we're not together) did some shit about a month ago. No penetration though. But then, about 8/9 days ago we had sex. He didn't wear a condom but I don't THINK he came. When we had sex my period was already one day late, but it still has not showed up. I took a pregnancy test like 3 days ago and it was negative, but that was only about five or six days after the sex so, was that too soon to take one? When should I take one again? I'm not having any weird symptoms but I have had some period cramps with a bit of pressure but the period never came with it, and I've been extremely tired like sleeping until 1-2 o'clock where normally I only ever slept until like 10-11 but I'm very tired. Besides that no symptoms that I've noticed. Please help??