First of all stop and breath!! Don't worrie about it so much you can make your body think you are so clam down. What you first need to do is figure out if you are or not. Take a test or go to the doctor to get a blood test. The doctor can't tell your parents why you went so don't worrie about that. And just cause you have a child with someone does NOT mean you need to marrie them! You marrie someone cause you love them no other reason!! Are you having any signs of being pregnant? If your having sex you need to be safe! There are so many stds out there and you don't want a kid so get on birth control and USE condoms!! If your mom is an understanding person talk to her she can help more then you think!
Good luck with everything! N please don't get married because of a child!