Very glad it all worked out for you & your DH.
But not convinced it's wise - no matter what OP chooses to do about the pregnancy - to put any weight whatsoever on whether the relationship survives.
No matter what OP decides, no matter what some PP imagine about him "coming round" (ie eventually accepting a pregnancy) this relationship doesn't need encouragement to survive, it needs a bullet between the eyes.
I too reckon the guy's lying with his crap about He said he always felt he couldn't have children so it would never happen. Apparently he always thought it was a case of see if I got pregnant and see how we felt at the time on if we carried on.
& as is clear from OP's adamant knowledge that she would never, ever have agreed to do that - her partner doesn't seem to have the first clue about the nature of consent, or as PP observed, bodily autonomy.
He encouraged OP to conceive on what he presented as a certainty, then when he wanted to backpedal & change his mind like he's returning goods to an internet shopping site, he pretends that certainty was only ever a whim.
No woman should waste herself on a man like that. A man prepared to play dice with her body, who is prepared to lie to get her to terminate, & whose reasoning (even though it's likely a backpedalling lie) is that it's fine to "order" a baby then tell the "manufacturer" he's changed him mind, no biggie, just get rid of it love. He's either pretending, or actually believes, that termination is a breeze for women who thought they were joyfully TTC their first child with a beloved & committed father-to-be.
Whichever it is - it's the manoeuvre of an untrustworthy selfish little prick, & OP would be unwise to believe a single word out of his mouth again.
I am so sorry for this devastating turnaround OP. 