Babys Head Engaged?

Hi all I am 37 wks pregnant with my 1st baby and I was wondering how do you know that your babys head is engaged, my bump has dropped alot and is very low.

Well from what I can remember at that stage I could feel a lot of pressure & the urge to pee a lot! But ask at your next hospital/GP appointment or else they might just tell you, I know my midwife did.