at twelve what should i do ?

I am 12 years old and I have a boyfriend we were home alone at his house seen as his mum and dad were at work for another four hours when we got in. When we arrived we sat on the sofa switched the telly on and just watched telly for half an hour. My boyfriend got nearer to me and put his arm around my shoulder and i kissed him on his lips before we knew it we were snogging it got out of control we took of it others clothes in the bedroom and before we knew it we were having like grownups. No protection nothing. I have heard it was dangerous and I havnt had my period. I think I am pregnant. Help me. Only one person knows about this and its my boyfriends mum she was the one who caught and stopped us and had a talk with us. My mum doesnt know HELP.