how to tell baby daddy

So im about 5 months pregnant. My boyfriend and me knew i was pregnant when i was 4 weeks and decided to get an abortion and i went to get one at 6 or 7 weeks and a month ago i found out that im still pregnant and i havent told him yet. I was bleeding and haven't gained weight so i didn't know until i went to the clinic to get birth control. They told me that maybe it was twins or the baby was to small so i had a failed abortion.. how can i tell my boyfriend im still pregnant?? This will be my 5th baby