Implantation bleeding or period??

So, last year around July I got my second and last depo shot. My bf and I decided we would start trying for baby #2. I finally had my first period since April of last year at the beginning of January. Normal period that lasted 4 days. February 1st I have my next one and it lasted about 7 days. We had sex a few days after I stopped and then Monday this week, I started spotting some really dark brown blood. That lasted for 3 days and then stopped. I go to the bathroom tonight and now I have some really bright red blood, just spotting. I know my body has yet to go back to normal and I really thought it was implantation bleeding, but now I’m not so sure. This will be 4 days straight of spotting. I think I got my hopes up 😞 Help a girl out!