Thank you for your query.
Haematuria during pregnancy
could indicate a urinary tract infection
, not necessarily detected by examination.
Also, it could be due to reasons like renal stones
, compression by the pregnant uterus
, or infection of the upper urinary tract.
You need to have a complete urine examination, including urine routine and microscopic analysis and a urine culture.
I think you should definitely call your doctor about it, as you are already having a high risk pregnancy , also undetected and untreated urinary infection would cause preterm labour.