Stressed i tested -ve for mgen at day 10, and at day 22 (although possible false due to doxycycline?). swabs showing no pus at day 30 & 40. tip of penis very uncomfortable during day, ache in testicles and lower abdomen. -ve all other stis. any ideas?

Your negative test result is conclusive and you should believe it. M gen is not known to cause the symptoms you describe. Check out the male chronic pelvic pain syndrome (CPPS); google has several good sources. The wikipedia article is good; also good info from the Stanford University dept of Urology. Please stop asking about M genitalium on health tap.

You are worrying too much. It is like what happens to some med students. They think they have symptoms of the disease they just studied. . Discomfort of penile tip- if organic would not just be in day time. If symptoms persist pl see a Urologist - for peace of mind