New pediatrician...

Ladies I know what I have done and it messed up my whole relationship but I’m glad my bf is still sticking by my side. This is a long story and I also don’t want to get into it since it is long. So when I had my baby I thought it was my bf turns out it wasn’t okay my baby had his first doctors appointment and we put down everything about my bf and his family then later on we found out the baby wasn’t his. The biological father of the baby isn’t around we don’t talk at all he hasn’t met the baby only seen him in photos but probably about 4 pictures and that’s it. He then blocked me in everything and so did I. My baby has his appointment tomorrow at his new pediatrician office. I really don’t know any history on the biological dads side. Should I just leave it blank or should I try and get in contact with him or his sister at least. My bf was with me throughout the whole pregnancy I know what I did and I regret it. Don’t ask why was I that dumb enough to do that and wear protection. It’s not only my fault the dad had his part to he wanted to meet the baby but he was “scared” and it got me mad because apparently he was t scared to finish inside like I told him I didn’t force him to do anything if he did it he should have stepped up and gave me a plan b pill with his money. Whatever though that’s the past my bf is currently stepping up as the father we don’t ever bring up he isn’t the dad we are both okay with him raising him as his own. He can make choices when it comes to the baby since he was there since day 1 and loves this baby as his own. Let’s just say its his kid. But I really need advice what should I do with the questions they ask at the office about the dads side? Thanks in advance. Also I would love to reply to any of you but I really feel like this post needs to be anonymous. But I guess if you guys have any questions I can just message you but would like this to be between us because this caused so many problems and now it’s getting a bit better.