Did you sign a contract?
They can't sack you for no proper reason.
My girlfriends sister had started work in a shopping centre, then after about a month there she found out she was about 3 months pregnant. Had to tell the shop of course so she wouldn't be doing lifting and such.
So what did the shop do...sacked her.
They said she was always late and didn't turn up some days. Was completely untrue - result 1 years compensation salary and her job back. She said stuff yer job ya creeps and took the money!