10 months and counting

So I have been with my fiance for 3 years. It will be 4 in june.. we have a date set to be married September 7th 2019... i am currently 5 months pregnant wit his baby. It's a girl. I have another son that is not his who he treats like his own since my son was 3 and we met. Perfect guy right? Anyways main reason for this post.. I am emotional, yes. Things are bothering me that never did before, of course. Well things have been tough as any relationship can be..up and downs. but this morning my when I asked when my birthday was he did not know. He said I know it's in February but theres so many birthdays idk.. this hit me hard. I am supposed to be important. We are soon to be a family. I know everything about him. We are supposed to be married in 10 months. Should this change my thoughts. Am I wrong for feeling like wow I'm marrying someone who knows nothing about me.. he even brought home food the other day and it was something I have never ordered before and I hate. I asked him today what do you really know about me. Conversation flipped to what do I know about him! Help me am I just pregnant and over thinking or is it okay to feel very concerned.