I Been On The Depo Shot Since 2014 I Haven't

I been on the depo shot since 2014 I haven't been back to get my last shot I didn't want to be on it anymore But me and boyfriend had unprotected sex many time n I never felt like I was prego or anything but now I been feeling sick to my stomach constipated have soar nipples I eat way more than usual I'm constantly peeing I'm getting cramps in my lower stomach and I haven't had period I spot here n there so I'm wonder am I possible pregnant???