Doubting paternity

I swear this baby is his, I've never been with anyone else. We got pregnant immediately after coming back from a separation, and I suspected and confirmed I was pregnant right on week four of the pregnancy because of weird gastric symptoms. So two weeks after I moved back in we had positive pregnancy tests.

I've shown him on everything that I'm telling the truth, and the ultrasound tech confirmed that the timeline is exactly what I said it was.

But he keeps making shitty comments about it to people and expecting me to be fine.

ADDED: And I've offered and demanded that we do a paternity test so he will shut up about it. He says he doesn't want one and will raise it regardless as his. But it still pisses me off that he talks about me and the baby that way

I'm so damn sick of this. Anyone else going through it?