I need some advice.

Okay so me and my s/o have been in an open relationship since June 2016. For the last 7 months we haven't been using protection. I am on birth control and I do know you can still get pregnant on bc. So we are currently finding out soon if I am pregnant. I haven't had a period since the 1st of last month. Which makes me a few weeks late. I have all of the symptoms and all of that. So we were discussing the what ifs because he is about to pcs in the military. He wants me to get an abortion because he doesn't want kids  but the way I see it is I didn't do this by myself and this will be our first kid if we are. I'm scared and don't know what to do... help.