Not sure what's going on!!!

Okay so my last pregnancy I was having shortness of breath like something was weighing down my chest. I miscarried with my pregnancy. But lately I've been feeling shortness of breath again like it's hard to breath I have 17 days till my next period and have never had azma. I've been shakey and tired a lot lately but I'm not sure what it could be my lower abdomial has been feeling tight and a little pain along with my pelvic any advise on what I should do?