I was totally OCD about all of this in my last pregnancy, and when I still ended up having a baby with a birth defect, I gave up on it.
I am mostly chemical-free though anyway, mostly just because it's cheaper. I make my own soap and use that for all of my body/hair care. I also make my own laundry soap and other cleaners. Pretty much the only thing I buy is dish soap/dishwasher soap, just because I haven't found a good solution I can make myself that works well. I do buy those natural though.
I think it is important to do whatever you can to avoid chemical exposure, but also to realize that you're pretty much never going to be able to completely eliminate exposure. The only known contaminant associated with my daughter's birth defect is present in ground water, and just living within a certain distance of water that has high levels greatly increases your risk of having a baby with that defect. I struggled so much with guilt after we found out about our daughter's defect, thinking there must have been something else I could have done to prevent it, or that I had done something to cause it. But the reality is, you can't prevent most birth defects, because unfortunately, no one knows what causes the vast majority of them.
I'm super tired and losing my train of thought, but my point is, do what you can, but know that sometimes things happen, even when you do everything right. I hope this doesn't sound wrong/bad, I'm not trying to be that way at all, I'm just trying to prevent someone else from feeling the way I felt...