How to announce to unsupportive parent

Back story-I have a four year old daughter and a two year old son. My dad was surprisingly supportive about my first two kids, even though he was slightly disappointed with baby number two because I was a stay at home mom and didn’t have plans for college yet . Now im 15 weeks pregnant with another baby girl, im in college going for my bachelors in computer science, and I have a full time job. I need to tell him soon because it’s getting hard to hide. The father of my kiddos also has a full time job so we can financially support them but I have a feeling my dad still won’t be happy this time around. My second pregnancy was hard on my body I had a lot of complications and he told me not to have any more kids. I wasn’t planning on having another but I got pregnant on birth control and here we are 🤷🏼‍♀️ Does anyone have any ideas on how to tell him? I just don’t know the best way to go about it, I don’t want any negativity with this pregnancy and that’s why I haven’t said anything for so long.

Suggestions and ideas are appreciated, I’m panicking 😂