Tight stomach/ uncomfortable feeling

So I'm not sure if I'm pregnant or not (trying to wait out on a test) I experienced the whole suuuper tired, moody, gas, cramps and headache thing..all which seem to have worn off about 8DPO now I just have a real tight feeling lower abdominal and since I thought well I'm not pregnant I did wear a thing around my waist at the gym to make me sweat and it did feel really uncomfortable to wear which isn't Normal for me . My question is . Is it normal to have signs go away and still be pregnant ? Again all that I'm feeling now is just tightness in my stomach and I am 11DPO now mind you my cycle is all messed up I average out a 25 day cycle