What's going on down there?

I need some insight. I ovulated on the 13th of February. Hubby and I DTD on the 10th and the 13th. My period showed up 2 days early on February 25th but it was very light. Then on the 26th during the day it basically stopped. That same evening, it became a blood bath again and then continued only until early afternoon on the 27th. Now ive been spotting brown but only when I wipe with toilet paper. Nothing on my underwear. And im having mild cramps. I'm confused because my cycle is never like this. It's always 3 days long and on time. Pregnancy tests I've taken have been negative. But this is the same kinda thing that happened when I was pregnant with my daughter. I bled off and on until 14 weeks with her to the point of thinking I was having a miscarriage. Any idea what could be going on?