Zoe,
My situation was very similar to yours. My boyfriend was a lot older than me and when I found out that I was pregnant, I told him, his reaction shocked me, I thought he loved me, but he turned his back on me, my parents didn't support me, I thought I was alone, but I wasn't..there's always someone who will give you a hand to hold. My advice to you is that you should tell him right away, but most important of all this, please it doesn't matter what he says, don't let him put pressure on your shoulders to go and get an abortion, believe me that's not an easy way out, if he is not gonna support you and you think you just can't raise this child, please consider adoption, that's the best way to go if you can't raise the baby, give a chance this unborn baby to live. I gave birth at 15 and I went through a lot of things, but I made it and here I am and I will never regret the choice I made: To keep my baby, and here she is, a beautiful and healthy girl, she's 3 and half years old now, and really...every time I look through her eyes I'm 10000% sure I made the right choice. Best Wishes. keep in touch.