Question for smokers

Just found out I'm pregnant after TTC (and essentially giving up) for 3 years. I am a smoker, I had given it up before when TTC but started again after I believed we couldn't conceive. I am 100% ready to quit. But, I am terrified that if I quit it will send my body into shock and cause a miscarriage. I am so torn right now, I don't know what to do. I set a goal to quit by the end of this week but I honestly want to right now, but I don't want to do anything that could stress out my body. Anyone have experience with this? I am exactly 4 weeks today. Thank you all! 💙