Protein in urine? No infection?

Okay so I'm 25 weeks and EVERY SINGLE TIME I've have had my urine tested in this pregnancy I have had small amounts of protein and leukocyte show up, the sample gets sent away then I get told no infection present. Then at my midwife appt the other day(I don't have a specific midwife) I mentioned this to her and she checked back on my notes and was concerned this hadn't been picked up on before now. Then she rang me the following day and said that she wants me to come to my maternity hospital to see the consultant on Monday, didn't give any more info. Has anyone else experienced this or have any ideas??

Edit:has been present from very start of pregnancy and blood pressure is always on the lower side of normal