Seriously people, law school is infinitely less stressful than a job. You can blow off law school assignments and professors way way easier than you can job assignments and bosses. If you're pregnant during law school, you're going to get plenty of leeway, because the deadlines are just arbitrary dates set by professors. When you have a job and deadlines exist because the quarter is ending or because Customer X is having a competitive bid, bosses are not as forgiving.
Being pregnant or being a mother is going to make that task harder. If you want to argue how that would make it easier, I am all ears.
I know tons of people who had kids during law school. They actually outperformed the median in my experience. To answer a question above... do I think having a kid will make it easier on you? No. Of course not. But can it actually help you? Definitely. It will force
you to develop a routine and stronger habits. It'll force you develop more efficient study habits. Both of those will help you in your legal studies. Plus, you'll presumably have the support of your husband and a network of friends you'll likely make in law school. Not to mention that professors are going to be understanding. All these people telling you it must be either X or Y are exaggerating the entire law school experience. And it'll make all of your achievements seem that much more impressive. This is all based on observation, not conjecture. I probably would have thought otherwise too, but in practice, those with families always seemed to outperform those without. Take that for what you will.
Again, it boils down to this: If you want to have a family, do you think it'd be easier to be pregnant while studying and juggling your course load for 4-5 classes or while trying to juggle the demands of a dozen clients while appeasing your boss and doing doc review on the side? It WILL NOT get any easier. It WILL NOT get any less stressful. If you want to have a family, do it now, not while you're working 120 hours trying to distinguish yourself at a law firm.