Terrified of Dry Socket?

I had all four of my wisdom teeth surgically removed on Wednesday morning. My bottom left socket is aching and I'm terrified of developing dry socket. I only took 3 Vicodin pills before switching to Advil because of nausea yesterday. I've been following the dentist instructions including rinsing with salt water after every meal and no straws. I've also been on a mostly liquid diet for three days. My dentist stitched up all the sockets and I'll have to get them removed next week. When am I in the clear for dry socket and what are the early warning signs?