advice please!

Hi there, could I have some advice please? I have just found out I am pregnant with our 2nd baby, I have a son who is 9 years old. The problem is when I found out I was pregnant with my son at 17 years old my partners parents , especially his dad was very angry and against it said I had ruined his life but my partner stuck by me. Fast forward! We now speak to my partners parents and get on pretty well although my partner is terrified to tell his dad about this baby, and it's really getting me down and worried as he's making me feel worried now , please help what's the best thing to do? We weren't gonna tell them till the 12 week scan but I just don't know if I can worry for that long about what we are gonna say to his dad???