I need some serious and quick advice..?

I honsetly think i am pregnant even though no one else knows and i still haven't taken a test to find out forsure. I need to talk to my mom about it but I am scared to do so. I am only 17 and naturally not ready to be a parent and my boyfriend just lost a baby with a past relationship and I have no clue how I would tell him not only because he lost the child but this would be his second in his short 15 years. And also because I'm not sure i want to go through with the pregnancy. I have been trying to think of a way to get a secret abortion without anyone knowing about it but don't want to live with that type of regret. And I don't think my boyfriend would let me give it up for adoption, He would almost force me to keep it... what should i do.??