What you're describing is what happened with Grace, she was about 1 yr old when my milk went away while pg with Max. She chose to wean, she never liked nursing beyond food. Her doctor let me give her regular soy milk starting at 11 months (she was cows milk intolerant). She was fine with that and weaning was harder on me than her, but by then I was ready for a break, knowing I would be nursing a baby again soon. Every mom is different...
I know several moms who nursed throughout their entire pregnancies, babies didn't mind very little milk, and then tandem nursed after baby was born.
Depending on your pregnancy (you'd have to sudden wean if you have preterm labor, etc) you will or won't be able to continue. This time I have weaned Max at 10 weeks pregnant because I simply couldn't consume enough calories to feed the twins, myself, and make milk. I was absolutely exhausted. :cry: But when you get pregnant, you have to change the mindset to caring for the baby(ies) inside of you first, which is hard!
Best of luck and I'm here if you want to chat more about it.