😬Could I be pregnant?? So not ready 😬😬

I have 3 kids and my baby is a year. So I’m on birth control a low dose. I have been for a year now. I started spotting two days before my period light spotting not enough for a pad, I thought it was my period because I had and still do what I thought was period cramps.(back pain uterine cramping). The amount of spotting has slowed to something on the toilet paper every now and then. Still some cramping but mainly back pain. No uti I know the feeling of those. My question is could I be pregnant even with taking birth control?? Keep in mind it has never affected my period in a year. I’m on pills and I don’t miss.