How early is too early to take a test?

Hi ladies!! My period is eight days late. (my boyfriend and i always use condoms) Usually something like this would not scare me but lately my back hurts so badly at night that I can’t fall asleep. (it might just be a chiropractor fix) But during the day all I can do is sleep. My boyfriend and I last had sex on Dec. 16th. Would it be too early to take a pregnancy test? Should I wait a few more days to see if my period comes? Please please give advice