Unplanned Pregnancy Fear

I’m about to be 30 years old and have been in a long term relationship for the last 10 years but not married. I just found out that I’m pregnant and I’m terrified. I’ve always wanted kids, but I always wanted it to be perfect. I have a full time career I’m still building, as does my partner, and we have our own apartment (2 bed 2 bath) On paper it sounds like this is the perfect time, but I’m so scared it’s not. What if this is a mistake? My partner wants me to continue the pregnancy and reminds me this has always been in the plan, but idk I don’t feel ready. Until I saw those two pink lines I would have said I would be happy, once I confirmed I’m pregnant I am not, I’m scared. Is this normal or should I really consider this to be a sign I’m not ready