Could I be pregant?!?!

Me and my boyfriend had sex last Saturday and he wore a condom and he didn't get off in me he pulled out with the condom on and got off and I started my period 3 days early but my period is usually always late then I usually have a really heavy period and this time it is supper light and on the tampon there is blood like normal but there are blood clots to and brown stuff I usally have the brown stuff right b4 I start or when I start my period it has been happend since this Friday and I have cramps like I normally do and I'm just sososo scared that I am pregant can someone help me:(