I dont know what to do

My babies father is going around telling everyone that hes not the father and i dont know what to he hasnt talked me since 10 weeks we just barley started talking last week so thats like 7 weeks without talking and he says he doesnt care that he has moved on and so i politely messaged that girl and asked her to leave him alone because hes not wanting to talk to me because of her and she told i should have just kept my legs shut i dont know what to do he keeps hurting my feelings i told him that and he said that he doesn't care