Pregnancy symptoms without pregnancy?

Ok so I don't know if I am losing my mind or not, but for the last couple of months I have had all the symptoms I did in my last pregnancy, ie, reflux, nausea, sore back, exhaustion, headaches, increased cm... But I'm not pregnant because I am breastfeeding my 6.5 months DD, and I have been getting my periods irregularly but still getting at least every month and we use protection?