Second marriage and having kids

I have older kids from my first marriage. Now I’m remarried to a man that I’ve been with for 7 yrs, but we just got married a year ago. We’ve been trying for about a year and have recently gone to a fertility specialist Bc I’m 40. Had my last child when I was 25. So far so good with all the testing, but I’m kinda on the fence on if I really wanna do this. My youngest is 14 and thinking about starting again is kinda freaking me out. Anyone been there done this ??