Hi OP, I’m so sorry you’re going through this right now.
Sadly you don’t have a crystal ball but I’m just wondering, say 18 months from now try and imagine two scenarios. 1) you aborted 2) you have a baby you wanted and your partner has come around to the fact that this is his baby and things are ok.
No one can see into the future. The pregnancy part would be very hard, wondering ‘what if’ in terms of who the father is. However, the withdrawal method is used by many many people as a contraceptive and has worked, for my friend, for ten years (she’s also been lucky to get preg v easily when she wanted to too btw). Please ignore the sperm wars thing - what on earth!!!! So most likely, v v high percentage it will be your partners. He wants a baby eventually so would he come around in the end (maybe not during the preg or even straight after but surely it wouldn’t be too long until acceptance of fatherhood sunk in)??
If you terminate and then can’t get pregnant later with your partner - this would be devastating to you both and may end up in the relationship ending in the future depending on how much he wants a child in the future. I have friends who have delayed having a baby (career etc) and now, after trying for several years, are facing the prospect that it won’t ever happen. Devastating for them. Thinking also of another friends sister who got preg by a guy v quickly and he didn’t want anything to do with the baby during the preg but then after he was born, the father realised he wanted to be a part of the child’s life. They later lost that child to an illness. Extremely sad.
What I’m trying to do is just think of the practical scenarios which may happen. If not helpful then please ignore - it’s such a huge decision, I didn’t want to just read your post and then not give you any input/something to ponder over. At the end of the day, the other posters are right, it’s your decision but in the future, things just may work out for you. Trust your instincts, listen to your heart and know that you will be ok.