bladder spasms ???

I'm about 3 months post op, but this bladder issue has not gone away, it started a week after my TAH, the doctor did place bladder stents in just before my surgery............i also had a cath. one week after surgery I started feeling this deep pressure midstream, not a painful feeling but it is uncomfortable..........I thought i had a UTI, so tried cranberry supplements and AZO, but this feeling remained, then bought an over the counter UTI test kit, came back negative, So I decided to go to the doctors office and have them do a urine culture, that came back negative too. could I be having bladder spasms ? has anyone else here experienced this ? I sure hope it is not a permanent situation.