Painful postpartum urination

Morgan
So... I have been experiencing some painful urination recently, off and on. I have noticed that it happens before and after my period, or sometimes in between. I've been to my GYN about it; no UTI, no std, no infection, nothing. Also, when I urinate, I feel this sort of light pressure in my uterus/bladder/supra pubic area. But I am completely clear of everything else! I am 7 months postpartum. During my vaginal delivery, I did have a first degree perineal tear & one dissolvable stitch. Does anyone have any ideas of what's could be the problem? Could the catheter during my epidural have something to do with it?