Bleeding help!!!!

I was trying to wait until af to take a hpt but I started having back pain two days and today started bleeding a little but I'm not cramping just mild back pain. Af is due on the 14th, two days from now. I never have back pain during af and usually I cramp very hard during my period as it starts. I've had naseua for about five days, my boobs swelled And became more firm a week ago. Jw if possibly just bleeding from implantation.