It does sound like you overdid things. Sometimes, even something as simple as being up on your feet for too long can cause a set back in recovery, so it doesn't have to be that you were out moving furniture or anything.
I'd say rest, drink tons of fluid, and keep a careful watch on both the bleeding and cramping. If you have even the slightest fever, I'd call your care provider right away. If the bleeding or cramping gets worse, you soak more than a pad per hour, the blood has a strange/funny odor, the cramps are bad enough that you need to take something for pain, etc, then I'd call now.
It's more concerning that you had already stopped bleeding and are now doing so again than it would be if you had been bleeding all this time, kwim? So it's definitely something to watch very closely.
Obviously if you are truly concerned, I'd go straight to the ER, but most likely resting, along with eating and drinking well, will have you on the road to recovery very soon.