Smelly discharge. Period related.

🦄🌸 • 26/AnaAmari&Arya💎👑. / Flourishing w Mommyhood, it’s REAL 🙌🏻

I don’t have an STD. I had this last month right before my period. But I’m having it this month too? I went to the doctor to have an STD Test and it came up negative. Should I go back and get retested? It only happens when I wear I certain pair of panties that go up my butt. Is it a UTI? I know it’s not yeast because there’s no white discharge. Could it just be from my period starting?