Love, please, stop stressing about this.
If are pregnant, it doesn't sound like the worst thing in the world. You're settled and sound able to provide. You want another child.
Your oh is the sticking point. He doesn't want another child, fair enough but the bulk of the responsibility for this is on him. Because he knows he risked it, twice over. He risked it in choosing to have unprotected sex and risked it a second time when he choose not to pull out in time.
You need to pull back from his panic and hassling of you and think about what you want if it turns out you are pregnant, because if you are he's going to ramp up the hassle and fear mongering and pressure even more - only this time it will be to pressure you into an abortion.
Choosing to have an abortion is absolutely fine of course. As long as you're totally on board with that and not coerced into doing so.
So carve out time now to think clearly about how you will deal with it if you are pregnant because you won't get a moments peace if you get a positive test result.
And - the argument that you both agreed not to have more children, because he didn't want them, doesn't hold water now. You're not bound to that agreement if you are pregnant because (1) its your body (2) its also your baby to make a choice (3) he took the greater risk (twice) when you slept together.
You can still decide not to go ahead with any pregnancy because you agree jointly not to, but make this a fresh decision and new agreement- not one you feel obliged to make because you went along with it in the past.
This is really, really important. Whatever decision you make, should you be pregnant, is fine as long as you make it of your own free will and not through the panicked coercion and manipulation of your oh because he won't take responsibility.
It's not the man who goes through this, it's you. So you get final say. He knows this, it's why he's panicking so much now.
Step back, detach yourself, and consider very carefully what you feel you would want to do.
That way, you'll be able to handle his panic and pressure while not worrying about thinking clearly.