Don't understand what's going on. . .

Ok so i started my period on the 5th and it ended 6 days later. Now for the past 3 days i have been having very light spotting. What is going on? The first two days i wore a pad and it was hardly nothing in it like it wasn't even worth wearing. Today i am spotting but its not drops its dots. My fertility widow begins tomorrow according to eve. I don't use any form of bc except that my husband pulls out. But last week he came in me twice. So idk what is going on can someone please explain? Should i worry because eve said it could be something serious like an infection. . . Help!