Pumpkin or Not???

He looks like he's finished, i'd cut him and turn him over to ripen the other side.

 

Cut the stem well away from the pumpkin, somewhere beneath where that 'bend' is. I've seen too many people cut too close and have infection get into the pumpkin via that route. And others leave it so long it gets knocked off and causes the same problem. It's a long time 'till Halloween.

My 'Halloween' pumpkin is only about 100mm diameter at the moment, is green just like your earlier pic, and will probably be the only pumkin I get this year (no female flowers on the 'giant').