How do I know if I have dry socket or healing?

Well, I'm not sure if anyone could help me. My dentist has been closed since yesterday due to bad snow. But I part of my baby tooth extracted yesterday, because it was interferening with my permanent tooth. It isn't a very big extraction. Probably the length of half of your fingernail. I smoke, and I am aware of dry socket. I've been smoking with gauze in my mouth to protect the wound, and earlier I looked into the extraction site, and I noticed that there was a white skin looking thing around my blood clot. Since this extraction was so small, didn't require stitches, and was non surgical, I didn't know if I was starting to get dry socket, or if it was healing already. The pain isn't to bad, but I also had a tooth filled right next to the part they exracted. I can't pinpoint the exactly location of the pain, but I am worried that I will get dry socket.