Not normal for me

So before I got with my boyfriend  a year ago I had not had sex for 3 years. Now I'm having sex regularly for a year now. After Maybe 5 months into the realtionship my period has been so weird. I've  always had normal periods light bleeding the first and gradually heavy by the 3 rd day then was done about my 6th day. Now,I'm hardly bleeding and spotting for 4-5 days really bad backaches and cramps and my flow starts about the 5th day and lasting 2 days only and I'm done.. I don't know what is goingon but I am scared something might not be ok in there and I fear going to the doctor just to tell me something really bad is going on and that I'm not fertile Ive been trying to get pregnant since Jan 2016 and nothing happens. If someone could tell me if they've had similar issues and tell me what it might be please help!😓