My ex boyfriend and I had sex and now I am pregnant. I was very drunk that night and don't remember whether I said yes or no. I want to have an abortion but he want to keep it, I am not even with him anymore so in my eyes he has no say, is this right for me to do?

If you are in the US, you can still legally abort the fetus without consent from a boyfriend. Many groups are fighting for bio father rights and some states have tried to pass legislation, but as far as I know, none have yet.
I don't see how a bunch of strangers online can tell you what to do. Start with friends, maybe family if they understand, and a counselor at a local Planned Parenthood or abortion clinic (yes, they have counselors who will just listen and help you decide - they aren't there to make you decide and use their services).
Do all this ASAP - the sooner you decide, the better.
If you want to elaborate about the ex here, feel free. How does he plan to support and care for a newborn all by himself, or is he trying to get you back, or get you involved on some level, or just what is he thinking?