Help with feedback

Jawoski

Ok so my wife n I had sex July 22. Her cycle wasn’t due to come on until aug 5. July 26 she wiped an seen light pink but then it stopped the same day. She’s been experiencing back pain, nauseous, urinating frequently. I’ve been experiencing headaches n slight nauseous. We tested on Sunday in negative. She’s cramping low abdomen.

Are these early signs of pregnancy?

Could we be pregnant and if so when’s the best time to test?