Fundal height - measuring too big??!

Jessica • Mom of 2 boys, 1 girl🧒🏼👦🏼👦🏼26 years young. Engaged💝💍
So since 28 weeks my fundal height has been more than the weeks I am pregnant. But at my app yesterday it measured 41cm and I'm only 36 weeks!!!!! Shouldn't my doctor be doing an ultrasound? I asked her if he's too big and she said not yet. I'm worried he's going to be like 12 pounds.