Were you prescribed Methergine (Methylergonovine Maleate)?
You may need methergine further. A mild to moderate bleeding/clots is normal for 48-72 hours, after D&C. But a sudden increased heavy bleeding with clots warrant a visit to ER for following reasons;
1) An ultrasound is usually done to see that uterus is empty.
2) Methergine may be needed.
3) With a fever and a possibility of infection, a reassessment is necessary.
Please feel free for your follow up questions.
I would be happy to assist you further, if you need any more information.