I have been feeling a burning sensation on tip of my pennis.My doctor did a test for sexually transmitted disease and it came out negative. He has prescribed DOXYCYCLINE MONOHYDR 100mg and have asked me to take it for 10 days. I have been taking it for last 4 days and there is not much improvement. Will it take so long for Symptoms to reduce? should I see my doctor again before finishing the medicine? Please advice.