WHAT IS THIS?!

So I don’t know maybe I’m a terrible person for this...but...

We tried for 18 months to get pregnant, I’m now almost 7 weeks pregnant, and I am so happy and excited!! But at the same time I have this like stinging sad feeling in the back of my brain that is so scared to have a baby, and I feel like I’m not ready for it, and like mine and my fiancé’s relationship won’t be the same, like it won’t be about us anymore (obv I know it won’t be)....and I feel so selfish for feeling that way...is this normal?? Has anyone else felt like this before...?

or maybe I’m just a terrible person..