I have pcos I can't go by miss period to take a hCG test. Took blood test 22 days after unprotected sex how accurate is this test?

Hard to tell. Since you don't know when you ovulate if you ovulate at all, it's hard for me to tell how accurate your blood test is. At least it is accurate at that time. If you're in doubt over potential pregnancy, repeat it in 3 -4 weeks.