toe nails separating

About 2-3 weeks ago my third toenail on my right foot seperated from the nail bed. A new nail has started growing. Now it's happening on my left foot, same toe. There was a little bit of a nail left at the bottom, so it didn't all come off but most of it did.
Does anyone know what causes this? As far as I know I'm healthy, I had a physical in April and everything was normal.
In the beginning of May I did have some sort of stomach virus (I actually think it was the samonella poisoning that they keep talking about, don't know if your immune system would affect that.
Do I need to go to a doctor? I kinda freak out when something abnormal happens and think the worst.
Thanks for your help!!