7DPO when should I test?

Regan

I’m 7DPO and I BD on my ovulation date and 4 days before. I am currently cramping a little bit and my back hurts which it usually doesn’t hurt this much. I tried taking a test and it was negative but the test has been in my car for two weeks and it’s like negative 2 out. It said it could mess up the test or should I just wait to see if AF shows up?