I was 17 weeks and the doctor said that I had an vaginal infection (which I don't why he didn't see that when he ran tests and took blood from me the week before). And that's what caused my miscarriage. Should I wait 6 weeks or can I try again now?

You need to wait at least 6 weeks to allow your uterus and cervix to heal properly. Getting pregnant too soon after a miscarriage can result it future miscarriages.