Some controdictary answers...

Stupid I am; but I might have got the tip of my penis (the urine area and around) exposed to a drop of vaginal fluid on the sheet. I can see the tip of my penis totally wet there; and if that's the vaginal fluid it should be there fresh (i.e. possibly just flow out from body). She's with underpant and skirt; so I would suppose the fluid went through the underpant and possibly skirt; then went on the sheet and I touched it. No direct genital-genital touch, no ejaculation, no hand job, oral, anal or vaginal sex.

I seek answers in different places but got difference answer...
Dr. EWH: No risk to HIV or any STD. No need to test.
Another Specialist in STD: No risk to HIV or any STD since he didn't think that fluid can be from the girl. No need to test.
Government HIV hotline: No risk to HIV since no penetration; low risk for STD. At most test for STD.
A counselor from a charity organization: low risk to HIV and STD. Test for all.

.... I am really paranoid. Can you give me some suggestions?

[diver58]

Take what Doc EWH said. We are not more knowledgeable than him. Opinion of the Counselor from the charity organization is not correct. There is absolutely NO RISK.

[ksxy]

hmmm... so vaginal fluid, after floating out, is not infecious?

[joggen]

HIV in vaginal fluid does not infect outside the woman's vagina.