<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi, i have a lump on the top of my vaginal opening. Its only recently been there. I noticed it after i had been on amoxicilin antibiotics. It hasnt gone down. Its not painful but i found it hard to have sex as he was struggling to insert the penis.  <response>: Hi madam, as you said it was difficult to insert the penis, so the lump might be big enough. There are few relevant things I should know before answering - your age, size of lump. Infact I would like to examine completely to arrive at a diagnosis. The size, color, situation, relation to other tissues etc. help us to have a diagnosis. The causes may be different in various age groups. So better option would be to have a consultation with a gynecologist. For proper treatment. 