Help please!!!!!

So yesterday I couldn’t take my birth control because they have been misplaced still had sex because I’m not to scared about getting pregnant and tonight I didn’t take it still don’t know where my pills are the few days before that I was late taking my pills and not tonight I’m having light back and front cramps and Idk why my period isn’t do for like 3 weeks and idk it it’s because of stomach problems like I can go to the bathroom like three times a day and I still feel backed up does ANYONE know what this could be??