"4 months window period is cover all STD/STI, right? "
I would personally agree with this; some say I might be too conserative, and yes with some std you can test earlier.
Assuming unprotected vaginal/anal sex:
chlamydia, gonorrea, NGU- 7 days post exposure
syphilis 4-6 weeks post exposure
HIV 3 months post exposure
HSV- 4 months post exposure
"But how much total test package usually cost in US? "
This depends, on many things, one is your health insurance, if your covered or not, on what type of service you get, you can order tests online for good prices, or you can go to your doctor or walk in clinics. Or if you want rapid test those are more expensive. I personally wanted to speak to a doctor and wanted quick results; did that and got peace of mind in 30 minutes for the above test, then including HepA,B,C, gon, chlamydia, and those results were ready in 24hrs. Cost was just over $1,200. I think we can say this is the most expensive route. Yah I had no insurance at the time.
4 months window period is cover all STD/STI, right?
But how much total test package usually cost in US?
Pricing is different all over the world.
Only need to test 1 time...gonorrhea and chlymida-1 week, syphilis-6 weeks, HIV-3 months, Herpes-3-4 months.
we can't provide the cost but see below for the periods
chlamydia, gono, ngu- 3 days post exposure
syphilis- 4-6 weeks post exposure
HIV- 3 months post exposure
HSV- 4 months post exposure