Pelvic pains- can anyone explain please?

So this morning I woke up with a really uncomfortable pressure in my back and on my hips. Throughout the day this pressure feeling (like a dull ache) has come and gone. Now the pain is in my back, butt and hips and feels like the pressure feeling is moving inwards, from my hips in towards my pubic bone of that makes sense?

Could this mean baby is dropping but slowly? I’m 36 weeks tomorrow.

Can anyone explain what it’s like when baby drops? Is it sudden? Slow? Does it depend? Thank you!