Pregnant after Miscarriages

I had 2 miscarriages back to back in 2019. My partner and I gave up entirely. We weren’t trying to get pregnant again until I found out what was wrong. Went to many infertility appts.. we tried to conceive again but for some reason it wasn’t working until recently I found out I was pregnant when we weren’t even trying.. Exciting but very scary. I’m so worried about everything going wrong and not being right. I just recently stopped smoking cigarettes once I found out. Had my first appt and blood work done. My levels were normal but progesterone was slightly low but nowhere near as low as the first 2 times of being pregnant. I would love some advice and some things that can help to keep my mind at ease.