No one can make the choice but me

I have a 6month old baby boy he is my dream (not in a weird boy mom way in a I've raise 4 of my sisters and really wanted a boy way) I just found out I am around 5 weeks pregnant after trying to get my iud put in twice and it coming out within weeks and trying forms of birth control that didn't kill my milk supply nothing worked and in-between it we had a little oops I took plan B come to a surprise it didn't work. Im honestly scared so many people have suggested its twins because it feels like im already showing and my hcg is high. My husband had an 8 year old as well I've bin going back and fourth on if I should terminate the pregnancy...for many reasons. Such as I dont feel entirely ready I feel more scared than excited. Although we could afford it we wouldn't be comfortable especially if its a different gender. I just bought a 2025 sportage to fit our family now however if we chose to keep the pregnancy where are we gonna fit our 8 year old stepdaughter who is 5'4 already between two already bulky car seats. Even after looking at cars we would be even more uncomfortable in our house and vehicle. And I guess I feel more scared than I was before now because of this reality check. I wasn't planning on having more kids until my son was atheist 3 years old. Again its a discussion only i can make everyone already knows im pregnant but I was thinking playing it off as if I miscarried again...idk what was the experience like for those who choose to terminate? Also if you did after having a kid did you regret it?