Positive OPK test. Not in fertile Window.

So I've been feeling kinda weird. I am about 8 dpo. I am not due for AF until Thursday but I took a opk because I heard you can use them to test pregnancy tho its not reliable. It was faintly positive but I'm not in my fertile window. Plus it's night (meaning I didn't use my fmu and it hadn't been 4 hrs since I last peed like box says if not using fmu). Should I take an actual pregnancy test or just wait until AF???