Is it possible not to have traces of blood in urine in a urine test 2days before a period?

It’s possible! Use wipes to clean around the urethra before giving the sample, and give a “mid-stream” specimen. This will avoid vaginal contamination of the urine as it exits the urethra.

Not only possible, it is normal to not have blood in urine at any time. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get HPV and Covid vaccines. Wish you good health!