I need some advice. Is there a way I could be pregnant?

About 3 weeks ago, me and my bf had unprotected sex. Ive been having all of these symptoms like back pain, headaches, ive been super nauseous after I eat, I've also been very exhausted. I had some light spotting after I was supposed to get my period but its been very irregular lately. I've been super hungry and the mood swings, they are just horrible sometimes. Is there any chance I may be pregnant? 😌