Hai ladies, opinions please?

Genevieve
Hey! Not sure if I am in my own head or not but....my period is 11days late today. Other than some serious bloating I don't have any symptoms. 
Although I am on the skyla IUD and my boyfriend and I are fairly safe, I'm still nervous. About two weeks ago I was vomiting from the stomach bug and a migraine (only lasted 24hrs) Just to be safe I took two tests, one that day and another a few days later. Both negative. 
I'm usually regular on the iud and never missed a period in the 9/10months I've been on it. 
Advice? (I know most probably aren't doctors, but just to relax my mind -_- lol) What's going on?