I can certainly feel my cervix this time, it is difficult with a belly but I am not overly big. My previous pregnancies it has been up far to high most of the time to locate it. So it doesn't surprise me that you can't feel yours, I imagine your belly is alot bigger than mine having twins.

Oh and yes, you would know if you found it, especially if it is hard and not dilated, mine being very soft and only just starting to dilate made me second guess myself.