Negative results.

I’m pregnant and have been having some burning after urinating, I just knew it was a uti or something and the doctor told me today that I was negative for everything. My vaginal swab tested for chlamydia, gonorrhea, and trich. My urine tested for uti. Literally they said everything came back negative but that doesn’t make any sense to me. Is it possible to have that feeling and be negative for everything?