I started hooking up with a guy in September and we have been hooking up ever since nothing serious, just mainly sex and now I’m pregnant?

I’ve known for a while and I’m 12 weeks pregnant and still haven’t told him yet. I’m planning on telling him got my first ultrasound yesterday and everything with the baby is healthy. He already has five kids, and he made a quick clear that he doesn’t want anymore, but it happens and now I’m pregnant. How do I go about telling him?
Updates
+1 y
Side note i was on birth control and didn’t mean to get pregnant but im sure he's bout going to believe because i wanted to have kids eventually
Updates
+1 y
Let’s get something straight I’m not upset I’m pregnant and I’m an independent women and rather do it on my own but he has a right to know
I started hooking up with a guy in September and we have been hooking up ever since nothing serious, just mainly sex and now I’m pregnant?
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