I'm a 40 year old women with 3 kids... youngest 19monyhs. I haven't had a period in 3 months but have all the pain and cramping and bloating. I have had lower back pain now also. I know feel really sore in my abdomen. I don't have any syptoms of pregnancy but have not taken a test yet. What could it be and is it serious?

There is no way for us to know this and we can't diagnose you online. The only way you will get a real answer is to see a doctor.