My period is gone? Any advice

I don’t feel particularly any more stressed than normal. I’m definitely not pregnant because I’m a virgin. I’m not eating any less food. It’s been 3 months of it being gone. I don’t feel sick. I occasionally get cramps but I get cramps throughout my cycle anyway and I think it’s more to do with digestion because they are after eating. Also I’m not on any medication or birth control. I’ve been on birth control a few years ago and that did stop my period because it was so painful but I’ve been off it for years. Should I be concerned