I've been having gas like crazy and tonight at work I was nausea.. I' have a headache and my nipples hurt like no tomorrow.. I took a few breathes and I was fine and my lower back has been hurting.. I'm not supposed to get my period for another 3 weeks.. now I'm getting that nausea again.. Me and my bf are TTC.. could I be pregnant, or am I just freaking out for nothing?