Fiance and mother of my child took off her engagment ring on a night on the town..?

What the F? she says she never took it off but I saw pictures from the night and NO RING! ? what should I think? this is the mother of my child and wife to be. We have been together for three years and I am the full time parent of our child because my fiance is in a year long army school....feelings on this? Oh yeah, I NEVER EVER get to go out and enjoy my friends or anything for that matter, I work 40-60 Hrs a week and take care of our one year old daughter....ugg.....