Wondering if I’m pregnant

Chardonnay

Last time I had sex with my boyfriend was late night on the 16th and my cycle starts tomorrow but I feel like I have been getting a few pregnancy symptoms like becoming extremely nauseous early morning and late night, I’ve became extremely sleepy and hungry. I also have been having bad lower back pain and I also experienced really bad cramps the third day after and I wanted to know is that a sign of implantation??