Creepy crawlies (how can ya tell if ya have )?

Not sure on this one, got little ichy bites all over my body with most of them being just above my pubic hair.. Cant actually see anything crawling round in there.. Just wondering bed mites or ?? How big are public lice? are they visible??? Somethings biting me i seem to get attacked when i sleep, im washing my linen on a daily basis