N.G.
When that happened to me, the nurse at the gyno's office told me to take four ibuprofen, put my feet up, and monitor the bleeding. If I soaked through a pad every hour for four hours, go to the ER. At that point, she said, I would be hemorrhaging, and I for sure needed medical attention.
Luckily the ibuprofen and foot elevation helped the bleeding to slow and I didn't have to go to the ER.
Definitely put in a call to your gyno and see what their advice is.