Photos disappeared on iPhone

Hi,

My phone is iPhone 6s and the iOS system was updated to 11.0.6

I signed up for the iCloud service and chose 200GB/month plan

This afternoon I checked my iPhone's photos and found that my photos disappeared

There should be about 11000+ photos on my phone while there was only 7200+

I didn't delete by myself and also couldn't find anything in the part of recent delete

But when I turn on my Mac Pro and checked the photos, all the photos and videos are there

Is it a normal situation ?

Because I afraid that if my phone connect to wi-fi Internet then those 11000+ photos and videos will disappear to 7200+, I didn't let my phone connect to wi-fi since this afternoon... (sad)

It will be nice that anyone tells me what happened to all this things and I will be very grateful to you

Thanks