You could try, Meghan. I am much...more padded this time around and we found it easily at 20 weeks. If you're 18 weeks, at the very least you'd hear the placenta. I so wish I could come over and give a lil listen!!!
Also, most babies really quiet with a growth spurt. The other day, my babe hardly moved at all. And now the last few days its really made it up- but I am more tired,hungry and thirsty. That's how I know the baby just gained a few.