Advice needed:my Bf Got me Pregnant without a purpose

This is a true life story so please don't comment carelessly. Our blog reader direly needs our advice as she says she's highly tempted to have an abortion.  Do search your heart and drop your most sincere advice below.

Hello Mercy, I may get tongue lashed for sharing my story on your blog but I need to talk to somebody. The man I'm dating got me pregnant without me knowing and I am furious. I am hurting. I am confused. 

I am in my final year, schooling in Nsukka and I've been seeing my boyfriend for over 3 years now. I actually met him when I was in year 1 and I had just lost my dad to an accident. It was a bad period for me, with a grieving mother, four more siblings, cash was short. My boyfriend came in and made things so much easier. He is not well educated, just has SSCE. He is a businessman based in Onitsha, 29 years old.

He visits me at school, I go over to visit him as much as I can. He supports me, I won't
lie.   

A few months ago we got in an argument over getting married and having kids. According to him, he has always wanted to start a family and has argued that we're financially ready. That it doesn't make sense for me to waste time and money waiting till I get a degree before marriage when he can financially support us. 

I told him that I wasn't ready and that getting my degree was important to me as I want to be established in life before having a baby. He reluctantly agreed and I thought that was the end of the conversation. 

We always use condoms so I've never been worried about accidental pregnancy. Though I noticed he would pull off the condom sometimes during sex. When I confronted him he said no, that it wasn't intentional. 

I was supposed to see my period last month, May 20th but it never came. I took a pregnancy test, behold it was positive. I'm still in shock and I don't know what to do. I haven't even told him because I know he'll be very happy. It really hurts knowing that he did this to me - got me pregnant on purpose obviously to trap me down. What kind of right thinking man does that?! Isn't this him being so selfish? If I get an abortion. won't my act be justified?

I am so angry, this whole thing is tearing me up, what can I do now? I am 23 years old, mercy. Please help me.