could i be pregnant or just late?

I generally have regualr periods and i'm never late, i was due on 15th feb but i didn't come on. Then on the 17th there was the tiniest bit of blood. I know it is a possibility that i might be pregnant since i slept with 2 lads since my last period, both without contraception. (1 being my boyfriend) he and i don't use contraception, silly i know but still. I have bad cramps which is unusual, i can't stop eating and usually i watch what i eat, i have to go to the loo like every half hour and feel a little sick. I read that pregnancy tests don't always show positive until a few weeks gone. I'm not sure i could wait that long to find out !!
Please reply someone, i don't know what it is or what to do. Thankyou

[jdlk]

If you were due on the 15th, then you are able to take a home pregnancy test.  There is a possibility of being pregnant.  The bleeding that you experienced could be implantation bleeding.  Get a HPT and if it shows a positive result then go to the doctor for verification.