I am having lower back pain lower stomach pain and pressure frequent urination that doesn't hurt, my tubes are tied going on almost 4 yrsi went to doctor yesterday took a urine pregnancy test came up negative..

And you told the doctor what your symptoms are, right? What did the doctor say? Perhaps go to a drugstore and buy 2 or 3 HPTs for a week or 2 from now, and to call him or her if you still show negative, and still have symptoms?

There are countless reasons you could have such symptoms.
I have them, and I'm almost 20 years past menopause. Mine are related to vertebrae compressing and pressing on lumbar and sacral nerves.