3 Weeks Pregnant?? SOS!!!

So this is the very first cycle my fiancé and I have had unprotected sex, and it just so happened to be in the peak of my ovulation window! I have no idea what symptoms to look for but I’ve had nausea every night, I’ve been peeing WAY more than usual, my breasts are a little tender and I’ve had some headaches. My period is due in 6 days, wen should I test? And do the symptoms sound like pregnancy??? I’ve never been through this before!!!