So me and my boyfriend have been having sex (the days with the hearts) everytime we have sex it’s unprotected but he always pulls out I started birth control on may 10 but I stopped it 2 days after so on the 26th me and him had sex and he came inside of me. Today my stomach has been cramping under the bottom of it and my back has been hurting a little I know it’s a big chance of me being pregnant but I just need a little more help getting this explained to me on how big of a chance I have

Also my lower back well my back in general has been killing me and under my stomach is cramping I also have started getting this type of discharge could anyone tell me what it means