Should I take the pill?

I had a D&C procedure 2.5 weeks ago. 1-2 weeks afterwards I was having cramps, feeling of pressure/pain, heavy discharge and no bleeding. I went to the ER and they saw a mass about 1x2 cm and said they don’t know if it’s a blood clot, retained pregnancy tissue, etc. They prescribed me misoprostol to expel the tissue and said it’s my choice whether I should take it or not and it could pass on my next period. I’m very torn as to what I should do? Take it? Not take it? I’m a bit confused as to why they left it up to me. 😅