Implantation bleeding? Help!

Ok ladies... I need your opinions!
According to this app, my period was a few days late. But my period is not like clockwork. I woke up this morning and found a little blood on the tissue when I wiped... Sorry if thats tmi. Cramps didn't start right away, but they started after I went running. I don't feel like they are as intense as menstrual cycle cramps, but I can tell they are there. And I hardly feel them for a bit, and then they seem to get more strong, then I can't feel them, then they get stronger, and so on... And it seems to hurt a little on the right side of my lower back as well as my lower abdomen. The bleeding, however, is light. Typically when my period starts, its heavy right off the bat. It seems to be a light brown/dark red. I did feel a tiny bit nauseous when I woke up this morning, but that didn't last long.
In your opinions, do you think this is implantation bleeding? And if you've experienced that, how soon did you take a pregnancy test after and get a positive? I'm trying not to get my hopes up. Haha