Grr my period is back

Tilley
It just ended 2 days ago. I have an IUD so it was super light for 4 days. This morning i woke up and I had really bad cramps and felt sick to my stomach. Went to the bathroom and it's heavier than before. Could antibiotics cause this? I'm very frustrated. I was so happy my period ended. This has never happened before. I've had regular periods since they started... 😣 is there anything I can do to speed it up and make it go away or make it stop all together?