Yes. When the head first comes out, all of the buds it's going to get are on it and they just get bigger. I can see that it's just a small head but it's ripe now. If you leave it too long, it will flower and get bitter.
After the main head is picked, broccoli often grows offshoots. The offshoots are about the size of that head. Read about it here.
Hmm... Well, I guess a single bite counts as "growing something I can eat". I'll give it another day (till it stops raining and isn't as cold outside) and cut it off. I should have paid attention to the seed packet more and given the plants more room and sunlight (or growlight). Well, I learn! And thank you for the insightful comment!!!
P.S. I think I found an offshoot right next to that tiny head. I might be wrong, but I will cut it tomorrowish. Learning new stuff is fun.
I sure does count! You can dice up and eat some of the stem too unless it is tough. It's great in a stir fry. One of the great things about gardening is there is always a chance for a do over.