Granny square help

I am new to crocheting and I have a question about my granny square. I started with a chain 5 and slip stitch to make a loop, Then a chain 3, 2dc, chain 2, 3dc etc until done with that round. After the last set of 3dc, I do one chain and then one single crochet to close the round.
Then I do a chain 3, and a one double crochet to start the corner on the new round.
Here is where I get stuck. I need to do 3dc, one in each of the 3 dc from the round before. I see 2 of the 3 easily, it is the 3rd one I can't find. Where is it? Is it hidden right where I am under the double crochet I just made in that corner? or is it at the very end before the next corner (after the last vertical dc stitch?)

I don't know which is right. Either stitch is hard for me to see and get the hook into. Is there even something else I am missing? I can't find videos of this at all.