Hello and welcome to HCM. Thank you for your query. The presence of an unpleasant odor from your vagina and the presence of a discharge could mean that you are suffering from a sexually transmitted infection. As you have not denied being sexually active, this could be the most likely cause. Although I am unsure about the contents of neo petron , I am assuming this is neo pyrazon , which is just a non-steroidal anti-inflammatory drug. This will only relieve you from pain and inflammation, and nothing else. In the tablet form, it can safely be taken during menstruation. I would advise a screening of all sexually transmitted diseases and laboratory analysis of your vaginal discharge. In the meantime, please refrain from all sexual contact, and wear clean and comfortable clothing (especially undergarments). Remaining asymptomatic (i.e. no symptoms) can take place during two stages of every infection. They are the incubation stage and if an infection is in the latent stage. Incubation stage is the time taken from entry of the infection-causing organism till appearance of the first symptom. This varies with every infection, and I cannot tell you the time taken for this until we find out about the infection you have. Latent stage is the stage which follows the incubation stage and the active stage. After the incubation stage, the individual starts experiencing symptoms (this is the active stage). When left untreated, some infections go into the latent stage (i.e. no symptoms, but infection is present). Again, this varies with every infection. So I will not be able to predict the exact time. I hope this is clear. I hope I have succeeded in providing the information you were looking for. Please feel free to write back to me for any further clarifications. I would gladly help you. Best wishes.