I am unsure if I should have a 3rd child

My husband and I have agreed to start trying for baby #3 which I’m excited about, but also very nervous. I think part of it is that I know my mom is going to be extremely busy as my brother & sister-in-law are having twins and she will be busy with them (they live with my parents) and my mil has mentioned it on numerous occasions that she doesn’t think anyone should have more than two because then you’re outnumbered. Between these two things I’m starting to feel like maybe this isn’t a good idea. However, I’ve always wanted at least three children and we have also talked about possibly four. I will be 31 in December and I want to be done having children by 35 which only gives me four years for 1-2 more children. I feel like I’m now all in my head about this decision and I just keep hearing my mil say how difficult she thinks it would be. She only had two children. But I also don’t want to put off having a third. Advice?