Single mom support

I’m a single mom already to my daughter who is 7 and I just recently found out I was pregnant with baby # 2 I’m currently 10 weeks and 2 days. Me and my boyfriend been together 2 yrs and in the beginning he stated “ oh I want one more” because he has a daughter already like me who is 15. So we both agreed OK but now the tables have turned and he doesn’t want anymore kids because he feels like he’s to old which he will be 40 in May🤷🏾‍♀️...I haven’t even told him that I was pregnant yet..I’ve been hinting at it but I really don’t know what to say? I’m 37 so abortion is out of the question we’re both grown and know what we did. Everything is going so good with us just afraid that it could be ruined once I tell him! Any advice on how I should tell him because I know it has too be soon ?