How much longer should I wait to take a pregnancy test?

My fiance and I had unprotected sex a little over a week ago. For the past few days, I have been really nauseous in the evenings and at night when trying to go to sleep. I have had cramps like I’m about to start my period which isn’t due for another 2 weeks, and I’ve been feeling this tightness in my stomach. How soon should I take a test? With our 5 year old, nothing would show up on a test til I was about 5 weeks.