Oh no. Is this what I think it is? What do I do?

Yes, a clear close up pic or two would help immensely, but it does look a bit like a male stamen developing. Go to my diary "Holy Mackerel . WTF?" for pictures of hermaphroditic flowers. This may help you to identify your plants more precisely. Hope this helps,... Organoman.

Not quite sure, if you could provide a few more pictures that'll be great! from this picture it seems like you might have a hermaphrodite ("Bi-sexual") with an open pollen sack/flower, though a more clear pictures would help determine that!

Hard to tell 100% from that pic, but it’s looking like one to me I think. Dang..I would have a good look at the rest of the plant and see if there are anymore. Pluck that one off before it opens and your good if no more show up. I had one of my banana bombs do this to me this round too(ironic...bananas on my Banana Bomb Lol). I found 3 late in flower so I pulled her just to be safe since she was at peak THC anyway already. But I believe you are still early to mid flower are you not? Hopefully just the one or 2 show up and you can pop them off before they open up and you can still finish flowering. But be warned that if you miss one and it opens... it’s hermy seed time for the rest of your crop around it.